Year	Number of
1990	105.89
1991	109.94
1992	114.29
1993	119.09
1994	124.15
1995	129.49
1996	133.79
1997	138.28
1998	143.19
1999	148.4
2000	153.96
2001	160.83
2002	168.25
2003	176.68
2004	185.57
2005	194.94
2006	206.07
2007	217.72
2008	230.64
2009	244.35
2010	258.95
2011	277.1
2012	296.64
2013	318.15
2014	341.16
2015	365.73
2016	391.36