Not easy to find the years the payouts changed, but we got it.

Powerball History
1992-04-22 to 1997-11-01: 5/45 and 1/45, 20 Year Payout
1997-11-05 to 2002-10-05: 5/49 and 1/42, 25 Year Payout
2002-10-09 to 2005-08-27: 5/53 and 1/42, 30 Year Payout
2005-08-31 to 2009-01-03: 5/55 and 1/42, 30 Year Payout
2009-01-07 to 2012-01-14: 5/59 and 1/39, 30 Year Payout
2012-01-18 to 2015-10-03: 5/59 and 1/35, 30 Year Payout
2015-10-07 to -Present- : 5/69 and 1/26, 30 Year Payout

Mega Millions History
1996-09-06 to 1999-01-12: 5/50 and 1/25, 20 Year Payout
1999-01-15 to 2002-05-14: 5/50 and 1/36, 20 Year Payout
2002-05-17 to 2005-06-21: 5/52 and 1/52, 26 Year Payout
2005-06-24 to 2013-10-18: 5/56 and 1/46, 26 Year Payout
2013-10-22 to 2017-10-27: 5/75 and 1/15, 30 Year Payout
2017-10-31 to -present- : 5/70 and 1/25, 30 Year Payout

partial source www.usamega.com