1910 Census. However, by the 1920s the Social Science Research Committee at the University of Chicago wanted divisions that were more natural and manageable than the arbitrarily-designated and numerous census tracts. The sociologist Robert E. Park led this charge, considering physical barriers such as railroads and the Chicago River to form distinctive and consistent areas within the city, which he deemed "natural" areas that would eventually merge into a distinctive identity. Ernest Burgess, a colleague of Park's who shared his thinking, was crucial in creating and naming the community areas. Initially able to identify 400 neighborhoods of the city, he considered that number excessive and trimmed it down to 80 and thereafter 75 by grouping related neighborhoods into a single community area. The Chicago Department of Public Health wished to present local differences in birth and death rates; it worked with the committee to produce the list of 75 community areas, which were divided into 935 census tracts. After the community areas were introduced, the University of Chicago Press published data sorted by them from the 1920 and 1930 Censuses, as well as a citywide 1934 census to help collect data related to the Great Depression, in what was known as the Local Community Fact Book. With the exception of 1970 (whose data was published in 1980), it continued this publication for every subsequent census through 1990, expanding in the 1960s to also cover major suburbs of Chicago. The Chicago Metropolitan Agency for Planning continues this work by periodically publishing "Community Snapshots" of the community areas and suburbs, the most recent being data from 2018 published . Only two major changes have occurred in the boundaries of the community areas. O'Hare was created from land that was annexed by Chicago in 1956 to control O'Hare International Airport. Edgewater was separated from Uptown in 1980 as residents considered being joined to it a detriment to obtaining aid for local improvements. In addition to these two there have been minor changes due to further annexations and additions to the Lake Michigan shoreline. Use and reception The areas are used for statistical and planning purposes by such professions as assessors, charities, and reporters. Shortly after their development they were used for all kinds of statistics, including movie theater distribution and juvenile delinquency. Although developed by the University of Chicago, they have been used by other universities in the Chicago area, as well as