12,702,379 people; 106 persons per square km (284 persons per square mile)
The population of Pennsylvania is approximately 12,500,000.
According to City-Data.com it is 16,778.
The 2006 Census estimate was 316,718. Pennsylvania has lost population in every Census since 1950 when it had a population of 676,806 residents.
The population of Lancaster County, Pennsylvania is 470,658.
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