Year	Number of
1990	1248.09
1991	1257.13
1992	1265.54
1993	1260.55
1994	1255.17
1995	1271.69
1996	1247.53
1997	1233.51
1998	1199.74
1999	1175.35
2000	1158.58
2001	1168.89
2002	1188.71
2003	1195.13
2004	1193.22
2005	1169.64
2006	1170.94
2007	1147.63
2008	1130.33
2009	1121.57
2010	1116.86
2011	1151.49
2012	1173
2013	1214.01
2014	1253.33
2015	1302.31
2016	1351