Year	Number of
1990	1150.98
1991	1241.67
1992	1224.43
1993	1229.59
1994	1240.5
1995	1267.45
1996	1203.66
1997	1153.11
1998	1108.99
1999	1094.67
2000	1095.32
2001	1062.26
2002	1098.42
2003	1131.98
2004	1178.53
2005	1254.48
2006	1246.83
2007	1258.77
2008	1275.41
2009	1297.13
2010	1317.1
2011	1357.41
2012	1405.84
2013	1457.29
2014	1509.82
2015	1579.17
2016	1644.87