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