Year	Number of
1990	1327.59
1991	1332.77
1992	1347.84
1993	1339.63
1994	1329.98
1995	1323.29
1996	1330.18
1997	1338.41
1998	1312.1
1999	1313.07
2000	1322.81
2001	1345.87
2002	1358.49
2003	1381.86
2004	1404.41
2005	1401.84
2006	1393.37
2007	1363.95
2008	1341.44
2009	1331.97
2010	1336.66
2011	1339.32
2012	1345.68
2013	1364.06
2014	1384.5
2015	1413.73
2016	1443.09