Year	Number
1961	101.84833333333334
1962	105.33029045643154
1963	107.43801652892562
1964	109.919341563786
1965	113.46065573770491
1966	116.107931316435
1967	119.13142857142857
1968	120.3287225386493
1969	123.2765612327656
1970	126.11156022635409
1971	126.61321514907333
1972	129.3590361445783
1973	131.42433947157727
1974	132.72545889864327
1975	133.63643595863167
1976	137.62289882651444
1977	137.94749403341288
1978	138.17478052673584
1979	139.39102564102564
1980	138.84646302250806
1981	141.5782258064516
1982	140.02428166734114
1983	138.13759611493322
1984	137.5961149332254
1985	137.19142047753945
1986	134.12698412698413
1987	127.49003984063745
1988	123.01587301587303
1989	118.11023622047243
1990	113.28125
1991	108.52713178294573
1992	99.52138570234749
1993	90.12364069715477
1994	93.59479553903346
1995	96.43925925925926
1996	84.24908424908425
1997	72.99270072992701
1998	64.23357664233576
1999	54.86918604651163
2000	52.34578627280626
2001	51.16916331750091
2002	49.45255474452554
2003	48.143382352941174
2004	47.51879699248121