Year	Number of
1990	83.38
1991	86.07
1992	88.47
1993	93.07
1994	96.36
1995	99.79
1996	102.89
1997	106.48
1998	113.03
1999	122.86
2000	130.21
2001	139.05
2002	147.05
2003	153.81
2004	160.4
2005	166.06
2006	171.19
2007	176.47
2008	182.49
2009	189.17
2010	196.57
2011	206.46
2012	217.25
2013	227.93
2014	238.84
2015	249.55
2016	258.52