(Currency in Circulation*1000000000)/(1000*Population)

Source: Board of Governors of the Federal Reserve System (US)  

Release: H.4.1 Factors Affecting Reserve Balances (data not included in press release)

Units:  Billions of Dollars, Not Seasonally Adjusted

Frequency:  Monthly

Notes:

Data prior to 1991 are from various issues of Banking and Monetary Statistics and the Annual Statistical Digest. Data from 1991 forward are calculated using data from the H.4.1 Release - Factors Affecting Reserve Balances.
As of March 1, 2019, this series is calculated as a monthly average of fred.stlouisfed.org/series/WCURCIR.

Source: U.S. Bureau of Economic Analysis  

Release: Personal Income and Outlays  

Units:  Thousands, Not Seasonally Adjusted

Frequency:  Monthly

Notes:

Population includes resident population plus armed forces overseas. The monthly estimate is the average of estimates for the first of the month and the first of the following month.
BEA Account Code: B230RC
A Guide to the National Income and Product Accounts of the United States (NIPA) - (http://www.bea.gov/national/pdf/nipaguid.pdf)