How much could an average investor have made by owning bonds in the past 5, 10 and 20 years?

Investors made between 1% to 2.5% annually from 2011 to 2016, 3.5% to 4.5% annually from 2006 to 2016, and about 5% annually from 1996 to 2016, if they owned the bonds that duplicated the major indexes of U.S. bonds, although some years were better and some worse: In 2013 the major indexes were down about 2% to 3%.

The results were about 5% annually from 1996 to 2016, although included some years of close to zero return.  Many investors own bonds as well as stocks to reduce risk and reduce the amount their total investment value could go down during times that the value of stocks go down. Investors should be aware, that although past performance is interesting, it is not a guarantee of future results.