Table 3.

 Standardised incidence ratios (SIR) for cervical cancer by time since diagnosis of cervical intraepithelial neoplasia grade 3 (CIN 3), stratified by period of diagnosis

Time since diagnosis of CIN 3 (years)	SIR (95% CI) for diagnosis during 1958-70	SIR (95% CI) for diagnosis during 1971-2002
1-<2	0.62 (0.23 to 1.64)	4.42 (3.48 to 5.61)
2-4	1.17 (0.76 to 1.80)	3.32 (2.83 to 3.90)
5-9	1.99 (1.50 to 2.63)	2.84 (2.46 to 3.27)
10-14	2.40 (1.81 to 3.17)	2.16 (1.81 to 2.59)
15-19	2.29 (1.67 to 3.14)	1.65 (1.29 to 2.10)
20-24	2.06 (1.46 to 2.92)	1.50 (1.07 to 2.10)
≥25	1.82 (1.37 to 2.43)	1.45 (0.88 to 2.41)
P for trend	0.005	<0.001