Source: U.S. Census Bureau
Latest Data: 2018
Release Timing: December
Frequency: Annual
Contact: Census Call Center, 1-800-923-8282

The data given here is for the percentage of the population aged 25 and older that hold a Bachelor's Degree or higher degree in the states. The years given refer to the year in which the data was collected, which is also the year for which the data pertains. Some questions on the Current Population Survey "such as income, ask about the previous year. Others, such as age, refer to the time of the survey."  The percentages were derived by dividing the number of persons with Bachelor's degrees and higher by the total number of individuals above the age of 24.  

Source: U.S. Census Bureau, Current Population Survey, Annual Social and Economic Supplement, 2018, "Educational Attainment in the United States."  The data for the states was downloaded from the CPS Table Creator.