Year	Number of
1990	78.9
1991	79.3
1992	79.03
1993	78.06
1994	77.42
1995	77.6
1996	79.21
1997	81.69
1998	85.12
1999	88.9
2000	92.87
2001	101.96
2002	112.38
2003	124.86
2004	138.65
2005	153.82
2006	161.04
2007	167.89
2008	175.07
2009	182.56
2010	190.64
2011	191.68
2012	193.27
2013	195.09
2014	196.99
2015	198.88
2016	200.87