Year	Number of
1990	95.57
1991	115.62
1992	135.23
1993	144.54
1994	159.3
1995	169.77
1996	175.35
1997	180.24
1998	185.3
1999	182.95
2000	185.27
2001	176.83
2002	169.45
2003	169.27
2004	172.45
2005	171.63
2006	172.38
2007	171.73
2008	175.13
2009	175.96
2010	177.82
2011	183.41
2012	184.96
2013	189.55
2014	191.62
2015	191.16
2016	192.41