Historical values of the Prime Rate 1955 to 2008

The Federal reserve has historical data on the bank prime rate going back to 1955.

Investopedia defines the bank prime rate as "The interest rate that commercial banks charge their most credit-worthy customers. Generally a bank's best customers consist of large corporations."

The prime rate is a fairly good indicator of interest rates in general. Often if you apply for a variable rate loan it will be based on the prime rate + X%. For example a home equity loan may be cited as prime + 0.74% if you have very good credit.

From the data at the Fed site I made graphs of the historical rates over history. First lets look at the rates from 1955 to 2008.



Yeah the rates hit 20% range in the 1980's. The maximum was 21.5% in December 1980. The average rate was about 10.1% and the median rate was 9%. The minimum rate was 3.25% recorded on Dec. 2008 as well as back in August 1955.

Now lets chart just the last 20 years:


In this period the average rate was 7.2%, the median was 7.5%, the maximum was 11.5% and the low was 3.25%.