Table 1

Survival status by year

Year	Population at risk	Number of deaths	Survival proportion	95% CI
0	4132	0	1.00	1.00 to 1.00
1	4068	65	0.98	0.98 to 0.99
2	3979	88	0.96	0.96 to 0.97
3	3884	95	0.94	0.93 to 0.95
4	3789	95	0.92	0.91 to 0.93
5	3694	95	0.89	0.89 to 0.90
6	3581	114	0.87	0.86 to 0.88
7	3479	101	0.84	0.83 to 0.85