The year of birth of the last 12 presidents (in order of birth) and their age when they became president:
1882 Franklin Roosevelt 51
1884 Harry Truman 60
1890 Dwight Eisenhower 62
1908 Lyndon Johnson 55
1911 Ronald Reagan 69
1913 Richard Nixon 56
1913 Gerald Ford 61
1917 John Kennedy 43
1924 George H. W. Bush 64
1924 Jimmy Carter 52
1946 George W. Bush 54
1946 Bill Clinton 46