One issue I see with this question is that there are multiple definitions of "safe queen". I probably actually use and/or carry about 30 or 40 knives each year, on average. Which means that I have more knives that I don't carry or use in a given year, than those that I do carry or use - again, in a year's time.
But I am not "saving" 95% of those "other" knives - I just didn't get around to using them, recently. My plan is to use and/or carry approximately 95% of my knives, over time. So by my definition, only about 5% of my knives are "safe queens". But if the definition of "safe queen" is what percentage of knives that you own have you not used or carried in the past 6 to 12 months - then it becomes probably 60-75%.