What percentage of women have had a sapphic relationship?

There are studies on this issue, and lots of anecdotal reports, however, it's hard to actually know for sure what percentage of women have had a sapphic, or, lesbian relationship, for many reasons, including...

* defining just what is a sapphic relationship - how a woman defines a sapphic relationship varies - so, just what makes a relationship sapphic? When it becomes sexual or ??? If, for example, if we looked, like Kinsey, at any relationship where two women were emotionally and/or sexually involved, at least one time, the percentage is higher (probably at least 20%) than if we set the standard at something like 'committed partners who've been together at least a couple of years' (probably 3-5% of women)

* there has been a bias in the research towards looking at male homosexuality and gay behavior or, when the behavior of the GLBT community is looked at, it is often 'lumped' together vs. teasing out the behavior of just the women

* men are traditionally 'taken' by the concept of two women together sexually so, some sapphic relationships are no doubt the result of a wife trying to please her husband This is a great question, and there is so much I could say, so these are my initial thoughts. If you'd like to discuss further, be sure to contact me!