Why was time delay set at 72 years for publishing census? Would 36 years been

Question:

Why was time delay set at 72 years for publishing census? Would 36 years been better?

In olden days a person's census info would have no value after so many years.. Now with so many people interested in genealogy, the info would be of more value if fresher.

Best Answer - Chosen by Asker: When they set the rule, 72 years was the average lifespan.

Federal U.S. census records from 1790-1930 are available to the public. To protect the privacy of people enumerated during a census, the records are closed to research for 72 years. The release date for the 1940 census will be 2012. (Individual 1930 census schedules were opened to the general public on April 1, 2002).