Year	% of revenue
1983	4.653422225200174
1984	4.582561985979181
1985	4.443380161770967
1986	4.473436819296999
1987	4.151902491512532
1988	3.828653535293061
1989	4.182850313713773
1990	4.518286450695463
1991	4.552735277065338
1992	5.4563631261400305
1993	5.814551650966145
1994	5.642606749165857
1995	6.292127166052667
1996	6.764880081148607
1997	5.671457860757285
1998	5.622353112982525
1999	5.388035391997183
2000	5.346958174904943
2001	5.5426285347797695
2002	5.770111433368951
2003	5.066604304769785
2004	5.032794442332732
2005	5.075323766720659
2006	5.0186917199657515
2007	4.982940913034354
2008	4.404316229905307
2009	6.661132383812657
2010	7.244767014319603
2011	7.248356778014981
2012	7.043158647366219
2013	7.53962732274718
2014	8.241746751038226
2015	8.044736106248502
2016	8.030426972677938
2017	4.156057942235484
2018	4.308640308647238
2019	4.763590523764299
2020	5.044369310292416
2021	7.3346407619442235
2022	6.836980704844377