How many Italian league have inter Milan won?

They have won 18 scudettos in the following seasons:

1909-10, 1919-20, 1929-30, 1937-38, 1939-40, 1952-53, 1953-54, 1962-63, 1964-65, 1965-66, 1970-71, 1979-80, 1988-89, 2005-06, 2006-07, 2007-08, 2008-09, 2009-10.