Year mm per year 1961 1651 1962 1651 1963 1651 1964 1651 1965 1651 1966 1651 1967 1651 1968 1651 1969 1651 1970 1651 1971 1651 1972 1651 1973 1651 1974 1651 1975 1651 1976 1651 1977 1651 1978 1651 1979 1651 1980 1651 1981 1651 1982 1651 1983 1651 1984 1651 1985 1651 1986 1651 1987 1651 1988 1651 1989 1651 1990 1651 1991 1651 1992 1651 1993 1651 1994 1651 1995 1651 1996 1651 1997 1651 1998 1651 1999 1651 2000 1651 2001 1651 2002 1651 2003 1651 2004 1651 2005 1651 2006 1651 2007 1651 2008 1651 2009 1651 2010 1651 2011 1651 2012 1651 2013 1651 2014 1651 2015 1651 2016 1651 2017 1651 2018 1651 2019 1651 2020 1651