The facts are that these are census tracts. If all the pictures are up, you can clearly see that some Census Tracts were in the beige or yellow colors in 1990, and ten years later the same tracts were in the yellow, yellow-green or olive green colors. Many of them have not grown in population, as their size has stayed the same. On the other hand, those areas where they have received more people in that ten year span reveal that the newcomers to those particular areas were primarily Hispanic. Thus, whether other groups fled or not really doesn't matter, as the Hispanic population percentage would go up either way. You can also see how many tracts were broken into two or three, particularly around Central Los Angeles. This represents a huge increase in population, and you'll also see that nearly zero of the tracts have turned in the direction of Hispanic to Non-Hispanic. Thus, with smaller tracts and increased percentages, this reveals that not only is the Hispanic population percentage increasing, but the shear numbers are huge.