From the stockmarket crash of 1929 to the federally declared bank holiday that marked its bottom, three and a half yearselapsed, and unemployment reached 25%.
Two years had elapsed since the Second Vatican Council convened by Pope John XXIII in 1962, which set out to dismantle the charge that Jews were responsible for killing Jesus.
Sixteen years will have elapsed between the government establishing a commission to look into the UK's pension problems and its key recommendation being fully implemented.
You can cash them in at any time once six months have elapsed, although there is a three-month earnings penalty if they're redeemed within the first five years.