Year	Number
1971	1569
1972	1492
1973	1434
1974	1718
1976	1421
1977	1529
1980	1569
1981	1538
1982	1588
1983	1604
1984	1391
1985	1523
1986	1534
1987	1521
1988	1572
1989	1686
1990	1601
1991	1607
1992	1514
1993	1554
1994	1579
1995	1595
1996	1618
1997	1675
1998	1691
1999	1779
2000	1790
2001	1765
2002	1716
2003	1745
2004	1654
2005	1608
2006	1611
2007	1650
2008	1528
2010	1748
2011	1909
2012	2058
2013	1701.80004882812
2014	1798.8310546875
2015	1824.75
2016	1932.69995117188
2017	1993.61499023438
2019	2102.0400390625
2020	2143.65991210938
2021	2102.419921875