It's difficult to go into this without drifting into advising you on your personal circumstances, which is something that we avoid doing, since we don't have all your personal details.
I have spent large swathes of my life filling in forms. I loathe forms that want yes or no to sometimes or maybe questions, which is why I add explanations if in doubt.
As I've said, I tend to add explanations to things, so if your answer is no, but not unambiguously so, I'd add something to explain it. If appropriate to your own case, you could use a phrase such as "not reliably and repeatedly because..."
What is absolutely necessary is to be truthful.
I realise that this may sound vague, but as I say, we have to be careful about giving individual advice when we're not in a position to interview you and discuss all the relevant information.
