A visualization for U.S. Metro Areas Violent Crime Rates by Type using the vega-lite-api.

Completed task: Cities vs crime rate

Observation : Detroit had the highest average violent per 100k from 1975 to 2015, and Nassau County N.Y. had the lowest average violent per 100k.

Future improvements:

1. add a Drop-down menu to filter by year
2. change violent_per_100k to crime rate

Questions:

1. How to add drop-down menu?
2. How to perform row-level divide operation in vega-lite-api?