When to apply ? if I was married to permanent resident and she become citizen

[ndex68]

I become green card holder on 6/22/2012, my wife was a green card holder but last year she become US citizen. When can I apply for naturalization ?
can anyone help? the reason I'm asking because the rule says after 3 years if married to US citizen and 5 years if married to green card holder but in my case my wife was green card holder but she become us citizen !