Year	Number of
1990	147.23
1991	151.34
1992	156.14
1993	161.25
1994	165.57
1995	169.69
1996	172.39
1997	176.26
1998	179.62
1999	184.98
2000	189.93
2001	195.09
2002	203.38
2003	211.04
2004	220.6
2005	230.81
2006	239.42
2007	250.89
2008	262.3
2009	274.09
2010	285.87
2011	296.85
2012	308.58
2013	320.59
2014	333.79
2015	347.12
2016	359