To be considered in reading data:
During World Wars and their aftermath data are scarcer and less reliable. Thus, economic liberty indices are more reliable for the periods 1850-1914, 1925-1939, and 1950-2007.
In the graphic representation of the estimates five-year averages centred in the last year are used (that is, the value of the index for 1854 corresponds to the average of the values over 1850-1854). Its purpose is to mitigate the volatility of the annual indices of economic liberty, largely a result of using outcome measures (de facto), rather than institutional settings (de iure), in its construction.