Table 1. General character of foundry workers.

		Production workers		Non-production workers		Total workers
		N	%	N	%	N	%
No. of workers		11,793	80.7	2,818	19.3	14,611	100.0
Person-years		150,714	80.3	37,020	19.7	187,734	100.0
Age (year) in 2001	20–29	1,533	13.0	620	22.0	2,153	14.7
	30–39	2,595	22.0	933	33.1	3,528	24.1
	40–49	3,856	32.7	696	24.7	4,552	31.2
	50–59	2,642	22.4	406	14.4	3,048	20.9
	60≤	1,167	9.9	163	5.8	1,330	9.1
	Mean age	44.7±11.3*		40.0±11.7*		43.8±11.0
Year first employed at foundry	≤1979	5,213	44.2	1,131	40.1	6,344	43.4
	1980–1989	4,104	34.8	856	30.4	4,960	34.0
	≥1990	2,476	21.0	831	29.5	3,307	22.6
Age (year) first employed at foundry	< 20	2,854	24.2	437	15.5	3,291	22.5
	20 – ≤ 30	5,720	48.5	1,747	62.0	7,467	51.1
	30 – ≤ 40	2,382	20.2	493	17.5	2,875	19.7
	40 ≤	837	7.1	141	5.0	978	6.7
	Mean age	25.5±9.2		25.1±10.3		25.4±8.9

^*p<.01.