Year	Number of
1990	143.88
1991	148.47
1992	153.73
1993	159.49
1994	165.61
1995	172.11
1996	175.07
1997	178.26
1998	181.66
1999	185.49
2000	190.02
2001	191.2
2002	192.97
2003	195.17
2004	197.79
2005	200.98
2006	205.65
2007	210.57
2008	216.13
2009	222.06
2010	228.47
2011	233.35
2012	238.63
2013	244.18
2014	250.17
2015	256.63
2016	262.96