Year	Number of
1990	203.39
1991	209.9
1992	221.08
1993	229.39
1994	238.74
1995	250.37
1996	250.94
1997	259.07
1998	265.01
1999	270.48
2000	278.84
2001	290.98
2002	296.36
2003	302.69
2004	312.23
2005	322.14
2006	337.02
2007	346.49
2008	357.77
2009	368.16
2010	378.03
2011	393.6
2012	410.19
2013	429.48
2014	448.53
2015	469.03
2016	488.78