Year	per 1,000 people
1960	2.472
1965	2.5
1970	2.881
1971	2.974
1972	3.156
1973	3.304
1979	2.694
1990	2.992
1991	3.189
1992	3.567
1993	3.582
1994	3.616
1995	3.621
1996	3.611
1997	3.68
1998	3.76
1999	3.698
2000	3.693
2001	3.706
2002	3.716
2003	3.715
2004	3.68
2005	3.634
2006	3.599
2007	3.563
2008	3.524
2009	3.529
2010	3.519
2011	3.525
2012	3.51
2013	3.483
2014	3.457
2015	3.451
2016	3.443
2017	3.452
2018	3.499
2019	3.542
2020	3.584
2021	3.654