Very difficult to gather any reliable research data on that. But the Church Doctrine, Teaching, and Law, as you well know, my dear Sinkspur, is there to set forth an ideal, and just because it cannot be perfectly enforced at all times is no reason to give in and condone it.
This is NOT HOMO BASHING. They just shouldn't be priests. If that means the Church has fewer priests, so be it.
The Church is being practical. There is simply no reliable way to judge who is, and who is not, a homosexual if the homosexual chooses not to reveal it.
Beyond that, there is ample evidence that celibate homosexuals have served the Church honorably throughout history and today.