The answer is worse than some and better than most, but the question has a problem. Los Angeles is such a large and diverse area that stating a particular percentage is misleading. It is much better for you to investigate each area that you are interested in.
Fortunately, the Los Angeles police department has a great tool for you to investigate each area you may be interested in. You can put in a particular address and find out about all the crimes that have taken place. http://www.lapdcrimemaps.org/
You can also get statistics for every area on Los Angeles through this page of the LAPD website. http://www.lapdonline.org/crime_maps_and_compstat