Year	Number of
1990	1304.48
1991	1312.38
1992	1319.81
1993	1313.65
1994	1308.84
1995	1326.38
1996	1302.49
1997	1289.62
1998	1255.46
1999	1226.65
2000	1205.09
2001	1212.84
2002	1227.79
2003	1233.95
2004	1226.63
2005	1200.67
2006	1203.93
2007	1182.5
2008	1167.01
2009	1160.48
2010	1159.4
2011	1196.71
2012	1221
2013	1266.65
2014	1311.25
2015	1369.5
2016	1424.73