Who were the Ivy League football champions in the 1900s?

1900: Yale (won 5, lost 0) 1901-Harvard (6-0)
1902: Yale (3-0-1)
1903: Princeton (4-0)
1904: Pennsylvania (4-0)
1905: Yale (5-0); Penn (4-0)
1906: Princeton (4-0-1)
1907: Penn (3-0); Dartmouth (1-0)
1908: Harvard (3-0)
1909: Yale (4-0); Penn (2-0)