Generally there are more job opportunities in Washington DC area. Salaries are also slightly higher there ~$110k/yearly vs ~$105k/yearly . You can do some comparison on the salary map: https://jobsquery.it/map
that map looks good for USA but certainly looks wrong and lopsided for some places in Europe. 100K in Romania? I don't think so. In Madrid the average is definitely not 61K, more like 32 or so. Looks like they really don't have enough data for many locations, and maybe they just once had a job posted for that amount.
