He broke Gerald Ford’s longevity record in December.
Gerald Ford broke Reagan’s record.
Reagan broke John Adams’s record which had stood since 1826.
1861-62 saw 5 living former presidents:
Van Buren, Tyler, Fillmore, Pierce, Buchanan
Not matched until 1993-94:
Nixon, Ford, Carter, Reagan, Bush 41
Matched again 2001-2004:
Ford, Carter, Reagan, Bush 41, Clinton
Matched again 2017-present:
Carter, Bush 41, Clinton, Bush 43, Obama
Jimmy Carter is around the same age as GHWB.