Year	annual %
1961	3.195990729569622
1962	3.182935941981081
1963	3.133685593272675
1964	3.061473694108421
1965	2.9637443338586547
1966	2.862731729014777
1967	2.7647699198759255
1968	2.6804718951197524
1969	2.6124611208222555
1970	2.7380247847712447
1971	2.9077602352706164
1972	2.868707682232724
1973	2.8372379424061602
1974	2.8044394728552535
1975	2.7513377235080756
1976	2.6834680722912205
1977	2.625722078093506
1978	2.5854709335688444
1979	2.703405819196949
1980	2.840628660138616
1981	2.831541086328146
1982	2.8747698905913976
1983	2.9157250696597576
1984	2.972863265148763
1985	3.052036805336047
1986	3.1353295889819015
1987	3.1749768776104483
1988	3.1236552336498558
1989	2.978941178803298
1990	2.8513186463257805
1991	2.8464494628566466
1992	2.8560415772899326
1993	2.8014119096664976
1994	2.6364083635939424
1995	2.130448158149689
1996	1.3400294512211377
1997	1.0380525365480018
1998	1.132916465870057
1999	1.1459178911376025
2000	1.0873017744660751
2001	1.0183450936668144
2002	0.950010862308778
2003	0.8488598779881509
2004	0.8474492536526916
2005	0.9074572156750196
2006	0.9026676472231513
2007	0.9008568322343649
2008	0.9362266732710469
2009	0.9884508901523493
2010	1.0481576104479715
2011	1.0964629095546494
2012	1.1229292101606412
2013	1.1180517412713693
2014	1.0806224961034063
2015	1.0133772368347453
2016	0.9249100025335512
2017	0.8203688103765384
2018	0.7020700511403024
2019	0.5831225274797899
2020	0.502344899805271
2021	0.43172111231105714
2022	0.3314082108616015
2023	0.2176722100031109