Assertion: rhythm method's failure rate | /r/HasProperty | first year
Facets:
Source sentences:
text: Failure rates (first year)
text: Failure rates (first year)
text: Failure rates (first year)
text: Background Type Behavioral First use Ancient Failure rates (first year)
text: Billings ovulation method Background Type Behavioral First use developed in 1950s Failure rates (first year)