It seems that the 2010-2020 era will go down in history as the "great hunt for yield." Traditional fixed-income investments like sovereign bonds pay a historically low yield (perhaps a 5,000-year low yield to be exact). This is largely because global central banks have kept rates below their equilibrium level to (try to) stimulate a highly indebted global economy.
While rates are at a 5,000-year low, the global median age is at a 5,000-year high (I think it's fair to assume that pre-1950 median ages were below 30 since expected life expectancy was much lower).