Most Senior SF Writer

Who, among the major writers, has been writing for the longest time? And who held the record before them?

Started writing Died Who? Years on Top
1851 1905 Jules Verne 54
1879 1930 Arthur Conan Doyle 25
1888 1946 H.G. Wells 16
1912 1950 Edgar Rice Burroughs 4
1919 1975 Murray Leinster 25
1928 2006 Jack Williamson 31
1937 2013 Fred Pohl 7
1949 still alive James Gunn 4

Interestingly, Jack Williamson had the longest run (ignoring Verne since we did not look for writers older than him.)