| Value |
Category |
| 1 |
calendar |
| 2 |
body temperature |
| 3 |
cervical mucus |
| 4 |
body temp. & mucus |
| 5 |
no specific system |
| 6 |
other |
Warning: these figures indicate the number of cases found in the data file. They cannot be interpreted as summary statistics of the population of interest.