Counting in crimes like drug sales is misleading. Selling drugs is really just a business opportunity, albeit illegal. Native Germans tend to have much better opportunities and more to lose. To some degree the same is true for robbery/burglary as well. It's economic pressure and incentives that make these crimes attractive, these people aren't so much immigrants but rather crime tourists (some of them from EU countries, mind you).

If you look at crimes without a profit motive, things tend to even out or turn around. You'll rarely see an immigrant responsible for arson or property damage, for example. In absolute terms, most crimes (that are persecuted) are of course profit-driven and the most crimes occur in poor areas.