Year	annual %
1961	3.4839228250300067
1962	3.888838161328195
1963	4.218589069472458
1964	4.179889133503451
1965	3.2760137933831572
1966	3.3012793876935405
1967	3.2986360094033955
1968	3.299993102803157
1969	3.300930498589622
1970	3.2636412552493397
1971	3.2924537896264354
1972	3.3357880650731033
1973	3.4247494452404226
1974	3.4898898746439215
1975	3.2266629996206433
1976	3.3557638346440655
1977	3.3056691166506056
1978	3.575680957762188
1979	3.8376620994456516
1980	3.8330606866398256
1981	3.84101445973981
1982	3.7411038374303303
1983	3.5700045357712042
1984	3.558606062219866
1985	3.5438894836621273
1986	3.5331856747324366
1987	3.5100135196765194
1988	3.45425622983673
1989	3.3355774301360412
1990	3.235100500109894
1991	3.1605377012234044
1992	3.0425403856021376
1993	2.976102216265602
1994	2.9345396956863112
1995	2.875970223906293
1996	2.82253492658964
1997	2.79713487378028
1998	2.7668550007461192
1999	2.7098232561634745
2000	2.67402260939123
2001	2.7623065507900435
2002	2.8180530879172068
2003	2.785544037087732
2004	2.7674169462894582
2005	2.7446418659339287
2006	2.67845973961893
2007	2.5998640420653203
2008	2.6221190093686886
2009	2.612393185219574
2010	2.5945098369301434
2011	2.5426988715520906
2012	2.5210631849212177
2013	2.512659706770279
2014	2.493025793123138
2015	2.4596743349253387
2016	2.408263733961064
2017	2.3723147875533073
2018	2.301508741642678
2019	2.2318127218472483
2020	2.136416007023726
2021	2.0094933311237924
2022	1.8059843237480777
2023	1.919852256962102