Year	Number of
1990	105.86
1991	110.99
1992	116.7
1993	123
1994	129.66
1995	136.64
1996	144.79
1997	153.22
1998	162.26
1999	172.04
2000	182.78
2001	192.42
2002	202.98
2003	214.71
2004	227.36
2005	240.99
2006	257.32
2007	274.8
2008	293.39
2009	312.7
2010	332.59
2011	348.94
2012	365.43
2013	382.11
2014	400.12
2015	420.14
2016	441.88