Table 11. Number of cycles of attempted conception required at different ages for various indicators of subfertility to be attained, for example 5.

	Median intrinsic conception rate <0.05	90th percentile of intrinsic conception rate <0.2	Probability of conceiving in next cycle <0.1	Probability of conceiving in next cycle <0.05	Probability of conceiving in next 12 cycles <0.5
Age 25	24	12	13	26	19
Age 30	18	10	10	21	14
Age 35	12	6	6	15	8
Age 40	4	0	0	6	0

The model of how fertility declines with age for example 5 is described in the text, with details of the computational implementation given in the supporting information (text S1).