Venus is 28 now and she started out when she was 14 so she's been out there for half a lifetime.

BBC: Tracy Austin on Venus v Serena

Hed spent half a lifetime in the bruising business of book publishing -- much of it at the top of the heap.

FORBES: Voyage of discovery

This means that over time much smaller estates would be hit with a rate that would confiscate nearly half of a lifetime of savings or business success.

WSJ: Review & Outlook: Death Tax Made More Deadly

It may surprise you to know that despite all of these advantages, the average Fortune 500 is extinct in 40 years half a human lifetime.

FORBES: Three Mistakes That Cause Big Business To Die

Obviously this country has gone through as tough of a time as we've seen in my lifetime over the last two and a half years.

WHITEHOUSE: Remarks by the President at a DNC Event

Globally the average fertility rate (the number of children a woman can expect during her lifetime) has roughly halved in the past half century, from five in the mid-1950s to 2.5.

ECONOMIST: The digressions of people power