Who won the college football national championship in 1920-1929?

Record is shown as w-l-t

1920 California 9 0 0
1921 Cornell 8 0 0
1922 Cornell 8 0 0
1923 Illinois 8 0 0
1924 Notre Dame 10 0 0
1925 Alabama 10 0 0
1926 Stanford 10 0 1
     Alabama 9 0 1
1927 Illinois • 7 0 1
1928 Georgia Tech 10 0 0
1929 Notre Dame 9 0 0