Year	Number of
1990	322.95
1991	315.65
1992	306.09
1993	302.39
1994	294.16
1995	288.75
1996	279.07
1997	271.42
1998	264.95
1999	259.2
2000	251.38
2001	244.67
2002	242.73
2003	234.47
2004	226.1
2005	223.74
2006	218.1
2007	214.89
2008	210.69
2009	207.28
2010	200.73
2011	197.56
2012	191.56
2013	185.24
2014	181.12
2015	182.06
2016	183.65