Year	% gross
1971	106.692909240723
1972	107.031158447266
1973	106.764518737793
1974	106.113349914551
1975	105.577423095703
1976	104.789817810059
1977	104.194206237793
1978	103.355758666992
1979	102.148323059082
1980	101.917907714844
1981	100.783996582031
1982	100.366500854492
1983	100.036163330078
1984	100.130447387695
1985	100.211982727051
1986	100.109031677246
1987	99.9705429077148
1988	100.325408935547
1989	99.7229614257812
1990	100.300987243652
1991	99.9645309448242
1992	102.887466430664
1993	105.64444732666
1994	105.440361022949
1995	102.199851989746
1996	103.223960876465
1997	103.570823669434
1998	102.888153076172
1999	103.352958679199
2000	102.13883972168
2001	101.571090698242
2002	101.665939331055
2003	102.861389160156
2004	103.654968261719
2005	103.47331237793
2006	103.293426513672
2007	103.30908203125
2008	102.505851745605
2009	101.09789276123
2010	100.511207580566
2011	99.9078598022461
2012	99.7986831665039
2013	101.002601623535
2014	100.616348266602
2015	100.177810668945
2016	99.8546829223633
2017	101.232490539551
2018	101.148811340332
2019	101.94847869873
2020	102.606079101562
2021	101.213020324707