Year	% of revenue
1990	25.285237407204423
1991	39.300879587503786
1992	28.307555737648947
1993	28.955956958671276
1994	24.81365778800833
1995	28.36802827965436
1996	28.93088506585439
1997	27.638733903678908
1998	29.438528399732554
1999	30.892145644051674
2000	35.04196918134133
2001	29.710916520277113
2002	24.807496033460875
2003	31.164306931772177
2004	37.12554114213243
2005	29.76512427689905
2006	38.108144148889735
2007	39.11609867929146
2008	36.292364922563216
2009	35.75769496126011
2010	25.57057647887879
2011	23.8556360779765
2012	36.31132963592031
2013	34.76915211195436
2014	36.2668858271579
2015	33.23703028291203
2016	28.79197825358382
2017	35.07831139161829
2018	31.757321875347742
2019	32.87221108159581
2020	38.229021247511305
2021	27.26058344115992
2022	22.799364183640552