So the statistics from Sweden aren't going to help us very much. Since first of all they don't know who the prostitutes are, but secondly also don't want to admit that their precious Swedish model has only endangered prostitutes rather then protected them.
But what could help us out are the statistics from Holland. After all, prostitution has been legalized since 2000, but even before it had been legalized it wasn't criminalized. This meant that prostitution before it was legalized was very much visible, as it is today, but just less protected. So the question now comes down to: did less murders happen in The Netherlands since the legalization in 2000? Because if indeed less murders where committed after the legalization, it would prove that legalization protects prostitutes better then not legalizing it, like how they did in Sweden.

The Netherlands legalized prostitution back in 2000. This means that the 127 murders do not only come from a period in which prostitution had been legalized, but also includes a period in which prostitution had not been legalized. In fact, we're talking about 13 years of legalized prostitution AND 17 years of not legalized prostitution. In short, we cannot make an automatic assumption that those 127 murders where purely the cause of the legalization, especially not since the majority of the time period came from a period before it had been legalized.
Fortunately though the internet can give us a hand here. There are a number of websites (source 1 and 2) which keep track of prostitution murders. They try to track back as many murders as possible, but as you can imagine, the older the cases are, the more difficult it becomes to find them back. This will re-assure us that probably the statistics from after 2000 are pretty much up to date, and as we go back in years it has become increasingly more difficult to find back data about it. This especially has to deal with the fact that since the introduction of the internet, it has become much easier to trace back information, while before the internet it's much more difficult to trace murders back. In short, the more recent the information, the more accurate they'll be.

Now to be fair in counting the number of murders, I'll count the number of murders from before and after the legalization over the same time frame, meaning from 1986 to 1999 for non-legalized prostitution murders, and from 2000 to 2013 for legalized prostitution murders, both a period of 13 years.
Doing a head count from the provided sources, I come down to 40 murders before the legalization (of which the last murder want back as far as 1989 which means I probably missed a few from the years before that), and 27 murders since prostitution has been legalized. To give you people a little bit of an idea, this means that before the legalization of prostitution in Holland every year around 3 prostitutes where murdered, while since it has been legalized this has dropped down to about 2 prostitutes each year. This means that since prostitution has been legalized, one prostitute less is getting killed each year. In total there have been 14 less killings in the same period after legalization in contrast to before the legalization. That's a decrease of 35% less murders since it's been legalized!

But let's also think about this for a moment. Why would legalizing a profession would make that profession less safe? Any normal functioning person can come to only one conclusion, which is that this doesn't make any sense at all. After all, if a job is legal, people have rights, people are protected and people aren't afraid and in need of hiding. This makes upholding the law for the police much easier, solving crimes much easier, but more importantly, preventing crimes much easier.
What explanation could other people give as to why pushing a profession underground would make it safer? Every idiot knows that pushing things underground only makes it easier for criminals to get their hands on. Look back at the 1930's and the prohibition of alcohol, did that make the alcohol industry more or less safe? I'll give you a hint, Al Capone wasn't arrested just because he didn't pay his taxes.
The only logical explanation a decrease in murders of prostitution by criminalizing it's clients would work, is if all the prostitutes would decide to either quit or move out of the country. That's something the Swedish government of course would love to claim, but we all know that's not true. Just because the Swedish government can't find the prostitutes, or very little of them, doesn't mean that they're not there. It just means it's gone underground, to places where authorities have no control, and justice is at the hands of those who've got the most muscle. And I can tell you right now, the prostitutes aren't the ones with the most muscles.

The facts stated in the tweet above is FALSE. First of all, the 127 murders came from a period twice as long as the Swedish number mentioned. Secondly, the majority of the 127 murders where committed in a period before the legalization (60% before, 40% after). And thirdly, since the legalization the number of murdered prostitutes have dropped with about 35%, proving legalization has caused a decrease in the number of murders committed on prostitutes. But most importantly, Sweden can't keep track of the prostitutes, because they've forced it to go underground, meaning they don't know which murdered women are prostitutes.

Bottom line is, since the legalization in Holland, less prostitutes have been murdered, Sweden can't tell because they don't know who are prostitutes and who are not. The number of murders in Sweden may very well be higher, since prostitutes are moving underground where everybody knows it's less safe. Just because the Swedish government doesn't count them, doesn't mean it's not happening. If that doesn't prove that legalization is far better then criminalizing prostitutes or it's clients, I don't know anymore.

Dutch version