Investing top 10 types of cuisines in New York City, we can find that Cafes have highest percentage of grade A. The reason is probably that cafes provide limited types of foods and drinks, which make them easy to prepare foods without violations. Cuisines that have less than 80% Grade A rate are Caribbean, Mexican, Latin, Chinese, and Japanese. These types of cuisines have different processing methods with different cultures. For example, Japanese sushi is made by bare-handed. Such culture difference might be the reason behind the
2. Cluster Analysis 
In order to see if there is spatial pattern existing in restaurant hygiene grading, I use K mean technique to cluster the violation scores against zip code.