Year	mm per year
1961	1292
1962	1292
1963	1292
1964	1292
1965	1292
1966	1292
1967	1292
1968	1292
1969	1292
1970	1292
1971	1292
1972	1292
1973	1292
1974	1292
1975	1292
1976	1292
1977	1292
1978	1292
1979	1292
1980	1292
1981	1292
1982	1292
1983	1292
1984	1292
1985	1292
1986	1292
1987	1292
1988	1292
1989	1292
1990	1292
1991	1292
1992	1292
1993	1292
1994	1292
1995	1292
1996	1292
1997	1292
1998	1292
1999	1292
2000	1292
2001	1292
2002	1292
2003	1292
2004	1292
2005	1292
2006	1292
2007	1292
2008	1292
2009	1292
2010	1292
2011	1292
2012	1292
2013	1292
2014	1292
2015	1292
2016	1292
2017	1292
2018	1292
2019	1292
2020	1292