I just realised one thing. The websites listed in top ten results of local business results, not necessary should be in top ten of local results. I checked and they are locating only on 5th page of Google's Local Business Search. In other words, Google not showing top ten of local results, it is selecting even from 5th page and placing on first page of local results. I found my business on 27th page of the results, but if i specify zip code next to keyword, then I'm stating number 1. Still it is in Manhattan, and there are many zip codes, my business in middle of the city, and its only on 27th page. You can find some other website which staying in top 10 only on 4th, 5th or 7th pages of local results.