Year	Number of
1990	121.97
1991	126.68
1992	129.79
1993	133.05
1994	137.63
1995	141.78
1996	146.71
1997	149.48
1998	153.99
1999	158.85
2000	162.36
2001	164.78
2002	168.32
2003	170.85
2004	173.5
2005	176.5
2006	179.27
2007	180.98
2008	182.61
2009	184.15
2010	189.78
2011	193.54
2012	196.48
2013	199.97
2014	203.13
2015	206.82
2016	210.78