TABLE 1.

Characteristics of Canadian Petroleum Cohort (1964--2006)

Characteristics	Males	Females	Total Cohort
Total	19,942	9,437	29,379
Alive	16,104	8,042	24,146
Deceased	1,350	319	1,669
Lost to follow-up	2,488	1,076	3,564
Total person-years	480,787	222,119	702,906
Date first employed (average)	May 04, 1979	June 20, 1980	September 13, 1979
Date of termination (average)	January 9, 1988	December 27, 1986	September 02, 1987
Average years worked	9.8	7.3	8.9
Average age at entry	27.5	26.2	27.1
Average age at last observation	54.4	52.4	53.8
Percent < 5 years worked	46.2	44.2	45.5