From...probably the G3's until about 2008 it was roughly 300 cycles. Then they boosted it to 500 once they started sealing them inside, and somewhere around 2010-2011 they upped it to 1000 cycles. (all of those are "It'll still hold 80% after that many charge cycles", not "They'll be dead by then")

Today, Macs, iPads and the Watch are 1000 cycles, iPhones are 500, iPods are 300 still.