Year	Number of
1990	130.01
1991	132.04
1992	136.27
1993	142.61
1994	147.01
1995	152.5
1996	160.87
1997	169.99
1998	178.69
1999	189.48
2000	202.7
2001	208.62
2002	217.17
2003	225.21
2004	234.76
2005	246.39
2006	258.16
2007	270.6
2008	280.52
2009	293.29
2010	307.38
2011	314.12
2012	321.76
2013	328.61
2014	336.04
2015	344.52
2016	353.09