Table 11.2.2.  Observed and expected exposures to wells G and H for twenty childhood leukemia cases

Case	Year of		Year of		Period of	Observed	Size of		Expected	Var	Proportion of
	Diagnosis	Birth		Residency	Cumulative	risk set	cumulative		risk set
							Exposure	sample		exposure		exposed

 1	1966		1959		1959-1966	1.26		218		0.31		0.26	0.33
 2	1969		1957		1968-1969	0.00		290		0.34		0.36	0.26
 3	1969		1964		1969		0.75		265		0.17		0.10	0.25
 4	1972		1965		1965-1972	4.30		182		0.90		2.23	0.36
 5	1972		1968		1968-1972	2.76		183		0.58		0.88	0.32
 6	1973		1970		1970-1973	0.94		170		0.20		0.20	0.19
 7	1974		1965		1968-1974	0.00		213		0.56		1.04	0.29
 8	1975		1964		1965-1975	0.00		239		0.99		2.78	0.38
 9	1975		1975		1975		0.00		115		0.09		0.03	0.25
10	1976		1963		1963-1976	0.37		119		1.18		3.87	0.40
11	1976		1972		1972-1976	0.00		132		0.24		0.32	0.18
12	1978		1963		1963-1978	7.88		219		1.41		6.23	0.40
13	1979		1969		1969-1979	2.41		164		0.73		2.56	0.31
14	1980		1966		1966-1980	0.00		199		1.38		6.00	0.39
15	1981		1968		1968-1981	0.00		187		1.14		4.20	0.35
16	1982		1979		1979-1982	0.39		154		0.08		0.02	0.23
17	1983		1974		1974-77/80-83	0.00		 84		0.25		0.45	0.23
18	1982		1981		1981-1983	0.00		  0		0.00		0.00	0.00
19	1983		1980		1980-1982	0.00		  0		0.00		0.00	0.00
20	1983		1980		1981-1983	0.00		  0		0.00		0.00	0.00