I think it's pretty basic. Clearly, most people fall one side of the fence or the other. Yeah, there are some that are true bi (50/50), but most of us are going to spend the majority of our energy towards one gender. It's a fundamental energy that we feel and need to have returned to complete the circuit.
As for me, I would certainly put 1% gay, even though I have never had a same sex experience of significance (nor am I searching for one). I recognize the sexual power of men (being one) and I appreciate it. But that's a long way from wanting to experience it directly. To me, sexual energy is strongly connected to polarity. Male to female, yang to yin. I really don't understand yang to yang or yin to yin as a energetic choice. Maybe as a drunken adventure - but not a long term choice.