Please answer a question about the following table 

header: President | Became Oldest Living President | Ceased to Be Oldest Living President | Age at Start Date | Age at End Date | Duration (Years, Days) | Duration (Days) row 1 : George Washington | April 30, 1789 | December 14, 1799 | 57 years, 67 days | 67 years, 295 days | 10 years, 228 days | 3,880 days
row 2 : John Adams | December 14, 1799 | July 4, 1826 | 64 years, 45 days | 90 years, 247 days | 26 years, 202 days | 9,698 days
row 3 : James Madison | July 4, 1826 | June 28, 1836 | 75 years, 110 days | 85 years, 104 days | 9 years, 360 days | 3,647 days
row 4 : Andrew Jackson | June 28, 1836 | June 8, 1845 | 69 years, 105 days | 78 years, 85 days | 8 years, 345 days | 3,267 days
row 5 : John Quincy Adams | June 8, 1845 | February 23, 1848 | 77 years, 332 days | 80 years, 227 days | 2 years, 260 days | 990 days
row 6 : Martin Van Buren | February 23, 1848 | July 24, 1862 | 65 years, 80 days | 79 years, 231 days | 14 years, 151 days | 5,265 days
row 7 : James Buchanan | July 24, 1862 | June 1, 1868 | 71 years, 92 days | 77 years, 39 days | 5 years, 313 days | 2,139 days
row 8 : Millard Fillmore | June 1, 1868 | March 8, 1874 | 68 years, 146 days | 74 years, 60 days | 5 years, 280 days | 2,106 days
row 9 : Andrew Johnson | March 8, 1874 | July 31, 1875 | 65 years, 69 days | 66 years, 214 days | 1 year, 145 days | 510 days
row 10 : Ulysses S. Grant | July 31, 1875 | July 23, 1885 | 53 years, 95 days | 63 years, 87 days | 9 years, 357 days | 3,645 days
row 11 : Rutherford B. Hayes | July 23, 1885 | January 17, 1893 | 62 years, 292 days | 70 years, 105 days | 7 years, 178 days | 2,735 days
row 12 : Benjamin Harrison | January 17, 1893 | March 13, 1901 | 59 years, 150 days | 67 years, 205 days | 8 years, 55 days | 2,976 days
row 13 : Grover Cleveland | March 13, 1901 | June 24, 1908 | 63 years, 360 days | 71 years, 98 days | 7 years, 103 days | 2,660 days
row 14 : Theodore Roosevelt | June 24, 1908 | March 4, 1909 | 49 years, 241 days | 50 years, 128 days | 0 years, 253 days | 253 days
row 15 : William Howard Taft | March 4, 1909 | March 4, 1913 | 51 years, 170 days | 55 years, 170 days | 4 years, 0 days | 1,461 days
row 16 : Woodrow Wilson | March 4, 1913 | February 3, 1924 | 56 years, 66 days | 67 years, 37 days | 10 years, 336 days | 3,988 days
row 17 : William Howard Taft | February 3, 1924 | March 8, 1930 | 66 years, 141 days | 72 years, 174 days | 6 years, 33 days | 2,225 days
row 18 : Calvin Coolidge | March 8, 1930 | January 5, 1933 | 57 years, 247 days | 60 years, 185 days | 2 years, 303 days | 1,034 days
row 19 : Herbert Hoover | January 5, 1933 | October 20, 1964 | 58 years, 148 days | 90 years, 71 days | 31 years, 289 days | 11,611 days
row 20 : Harry S. Truman | October 20, 1964 | December 26, 1972 | 80 years, 165 days | 88 years, 232 days | 8 years, 67 days | 2,989 days
row 21 : Lyndon B. Johnson | December 26, 1972 | January 22, 1973 | 64 years, 121 days | 64 years, 148 days | 0 years, 27 days | 27 days
row 22 : Richard Nixon | January 22, 1973 | January 20, 1981 | 60 years, 13 days | 68 years, 11 days | 7 years, 364 days | 2,920 days
row 23 : Ronald Reagan | January 20, 1981 | June 5, 2004 | 69 years, 349 days | 93 years, 120 days | 23 years, 137 days | 8,537 days
row 24 : Gerald Ford | June 5, 2004 | December 26, 2006 | 90 years, 327 days | 93 years, 165 days | 2 years, 204 days | 934 days
row 25 : George H. W. Bush | December 26, 2006 | Current oldest living president | 82 years, 197 days | Current oldest living president | 7 years, 173 days | 2,730 days
row 26 : President | Became Oldest Living President | Ceased to Be Oldest Living President | Age at Start Date | Age at End Date | Duration (Years, Days) | Duration (Days)

which u.s. presidents have ever held the title oldest living president? of these presidents, which ones held the title for over 20 years? of these presidents, which one held the title the longest?

Answer: Herbert Hoover