The following data is the current and historical 120% of Federal Mid Term Rate. As time permits, I will go back further in time.
Why is this rate important? As it pertains to early retirement, this is the rate used in some calculations for Reg 72(t) for an early retiree to be able to take penalty free withdrawals from their IRA prior to reaching age 59.5. Technically, 72(t)/SEPP (substantially equal periodic payments) uses a reasonable interest rate, which is defined by the IRS as not more than the 120% Federal Mid Term Rate for either of the 2 months prior to the first distribution.
If you do not understand the rules for setting up your 72(t) calculation, I highly recommend you talk to a professional who truly understands the calculation and rules. I charge $995 to set up the distribution, or $100 per hour to discuss and answer questions (hourly fee can be credited towards a calculation).
Here is a look at the most current (June 2020) and historical 120% Federal Mid Term Rates: