Table 2. Results of course analysis of patients with ulcerative colitis converting to colorectal cancer.

Years of disease (years)	Article (n)	Conversion rate (%)	95% confidence interval	Proportion (%)
1–9	1	0.069	0.004–0.008	23.8
10–20	6	0.012	0.01–0.015	36.5
21–30	2	0.019	0.013–0.025	15.0
≥30	2	0.016	0.012–0.021	25.3