Year	Number of
1990	153.27
1991	152.85
1992	159.85
1993	165.57
1994	162.77
1995	168.93
1996	172.1
1997	177.75
1998	176.1
1999	176.8
2000	171.74
2001	167.79
2002	165.9
2003	167.35
2004	165.44
2005	169.75
2006	169.67
2007	172.94
2008	175.3
2009	175.73
2010	186.99
2011	184.49
2012	184.47
2013	185.68
2014	187.07
2015	188.58
2016	190.1