Year	mm per year
1992	1162
1993	1162
1994	1162
1995	1162
1996	1162
1997	1162
1998	1162
1999	1162
2000	1162
2001	1162
2002	1162
2003	1162
2004	1162
2005	1162
2006	1162
2007	1162
2008	1162
2009	1162
2010	1162
2011	1162
2012	1162
2013	1162
2014	1162
2015	1162
2016	1162
2017	1162
2018	1162
2019	1162
2020	1162