Year	Number of
1990	1187.73
1991	1181.9
1992	1180.39
1993	1173.76
1994	1171.19
1995	1172.19
1996	1165.37
1997	1160.15
1998	1153.96
1999	1147.44
2000	1140.57
2001	1128.92
2002	1117.28
2003	1115.33
2004	1111.44
2005	1106.06
2006	1098.56
2007	1088.64
2008	1085.91
2009	1082.06
2010	1078.31
2011	1070.43
2012	1061.47
2013	1051.33
2014	1040.68
2015	1030.99
2016	1012.36