2010:
Syrian asylum applicants received: 421
2011:
Syrian asylum applicants received: 640
Running total: 1061
Number of reported rapes: 6532
Number of reported sexual molestations: 7762
2012:
Syrian asylum applicants received: 7814
Running total: 8875
Number of reported rapes: 6324
Number of reported sexual molestations: 7607
2013:
Syrian asylum applicants received: 16317
Running total: 25192
Number of reported rapes: 6017
Number of reported sexual molestations: 8797
2014:
Syrian asylum applicants received: 30583
Running total: 55775
Number of reported rapes: 6697
Number of reported sexual molestations: 9643
2015:
Syrian asylum applicants received: 51338
Running total: 107108
Number of reported rapes: 5918
Number of reported sexual molestations: 8840
2016:
Syrian asylum applicants received: 5457
Running total: 112555
Number of reported rapes: 6560
Number of reported sexual molestations: 10500
For rape there is effectively no correlation whatsoever. The comparison between the number of sexual molestations reported and the cumulative refugee figure gives a correlation so weak it probably doesn't exist, but let's look into this anyway. The higher the refugee figure in a given year, the higher the number of sexual molestations were reported, yes. However, as the refugee figure rose, so did the population, and an increase in the raw number of people would be expected to increase the number of sexual assaults even if the rate stayed the same. So a comparison between the proportion of the population that is a Syrian refugee and the rate of rape in the population is a better measure. On doing this not only does the correlation drop still further, but the apparent impact drops as well. The net result is that the correlation is weak enough for it to be genuinely laughable to claim that Syrian refugees has driven up the rate of rape in the country, and that even if you do claim this, then you can still only claim for every 1% of the population that are Syrian refugees, the rate of sexual molestations per person will increase by 0.000155.
It is also essential to note that the more stories about sexual assault are in the news, the more likely people are to report it. In 2016 such things were in the news far more often than in previous years. This is almost certainly a far bigger factor than the number of Syrian refugees in the country, if the latter is a factor at all, which it probably isn't.
Assumptions made include that there were no Syrian refugees before 2010 (this has no impact on the result given above as it would increase the number of refugees in every year), that no Syrian refugees left the country (in reality this would not be zero, and the more who left, the weaker the figures become, so the above actually gives a better case for your claim than what would be reality) and that the estimated number of reported rapes and sexual molestations for 2016 will prove accurate.
Here's the graph for the strongest case for your argument:
Incidentally, for rapes the R squared value is 0.15, and the correlation negative - in other words, the more Syrian refugees there were in the country in a given year, the fewer rapes there were per person.