highest point differential 2011 to 2020
highest point differential 20179 to 2020
highest point differential 1970 to 2020
highest point differential 1970 to 2019
highest point differential 1970 to 2014
highest point differential 1970 to 2009
highest point differential 1970 to 2004
highest point differential 1970 to 1999
highest point differential 1970 to 1994
highest point differential 1970 to 1989
highest point differential 1970 to 1979
highest point differential 1970 to 1995
highest point differential 1960 to 1995
highest point differential 1960 to 1996
highest point differential 1960 to 1997
