what is the average life of a bond
http%3a%2f%2fwww.morningstar.com%2fInvGlossary%2fGlossary.aspx%3fterm%3daverage_duration. Average Duration. Duration is a time measure of a bond's interest-rate sensitivity, based on the weighted average of the time periods over which a bond's cash flows accrue to the bondholder. Time periods are weighted by multiplying by the present value of its cash flow divided by the bond's price. A bond's duration will almost always be shorter than its maturity, with the exception of zero-coupon bonds, for which maturity and duration are equal.