Cyclists requiring treatment in US Hospitals 1991 to 2000

Year	Total injuries	Total head injuries	% head injuries	All injuries < 15 yrs	Head injuries < 15 yrs	% head < 15 yrs
1991	567,700	66,820	12%	381,450	50,160	13%
1992	607,615	70,616	12%	423,671	55,239	13%
1993	559,197	62,866	11%	377,369	46,516	12%
1994	570,985	65,688	12%	369,207	46,747	13%
1995	553,064	63,216	11%	339,866	42,843	13%
1996	533,501	61,192	11%	335,245	43,201	13%
1997	567,002	61,861	11%	350,546	41,261	12%
1998	597,280	66,890	11%	362,330	43,280	12%
1999	614,590	71,720	12%	378,260	47,920	13%
2000	627,160	73,750	12%	373,090	49,250	13%
Totals	5,798,094	664,619	11%	3,691,034	466,417	13%

Source: Consumer Product Safety Commission

Note:

The proportions of head injuries did not change over the period despite helmet use in the USA increasing from 18% of cyclists in 1991 to 50% in 2000.
However, cycle use during the period fell by 21%.
Thus those who continued to cycle were 40% more likely to suffer head injury by 2001 than in 1991.