Year	Number of
1990	253.65
1991	260.77
1992	269.08
1993	277.03
1994	285.46
1995	294.06
1996	302.4
1997	310.42
1998	318.95
1999	326.89
2000	334.65
2001	333.2
2002	332.11
2003	333.44
2004	335.14
2005	337.2
2006	335.95
2007	335.26
2008	335.14
2009	335.78
2010	337.2
2011	336.13
2012	335.28
2013	334.4
2014	334.13
2015	334.68
2016	334.73