Year	Number of
1990	113.54
1991	120.53
1992	127.53
1993	135.26
1994	139.51
1995	141.78
1996	140.37
1997	149.48
1998	154.8
1999	167.2
2000	172.19
2001	180.43
2002	185.87
2003	193.1
2004	199.9
2005	203.92
2006	202.05
2007	203.26
2008	204.05
2009	205.39
2010	204.48
2011	206.39
2012	204.67
2013	210.36
2014	216.53
2015	226.87
2016	235.44