If you check back you'll see that I made an earlier post in this thread which answers your questions. Though why you should assume that I carry a spare mask on every dive isn't clear to me - I didn't say I did. Nor did I say how often that mask has been used, (a) by myself or (b) by others. To answer those last two questions, the answers are (a) never, and (b) two or three times.
What is the relevance of the colour of the skirt of your mask if you're not wearing it?
What is the relevance of the colour of the skirt of your mask if you're not wearing it?