Year	mm per year
1961	1583
1962	1583
1963	1583
1964	1583
1965	1583
1966	1583
1967	1583
1968	1583
1969	1583
1970	1583
1971	1583
1972	1583
1973	1583
1974	1583
1975	1583
1976	1583
1977	1583
1978	1583
1979	1583
1980	1583
1981	1583
1982	1583
1983	1583
1984	1583
1985	1583
1986	1583
1987	1583
1988	1583
1989	1583
1990	1583
1991	1583
1992	1583
1993	1583
1994	1583
1995	1583
1996	1583
1997	1583
1998	1583
1999	1583
2000	1583
2001	1583
2002	1583
2003	1583
2004	1583
2005	1583
2006	1583
2007	1583
2008	1583
2009	1583
2010	1583
2011	1583
2012	1583
2013	1583
2014	1583
2015	1583
2016	1583
2017	1583
2018	1583
2019	1583
2020	1583