What i learned in my statistical analysis class is that if you evaluate 3% of things, you need 50% of one answer to report 1-2%
PRO can on good days, hit about 2000 in total, which has been done numerous times throughout it's history, from that 2000 players, you asked 60.
simple math says that 60 is about 3% of 2000, which means by law for you to say 1-2% of people use it, you would need to have between 20 and 40 people say yes to using it, but you said one person does, that one person, is about the equivalent to 0.05% of the playerbase number i've used. However because you took only 60 players, you got 1/60, which multiplied by 33.3periodic, equivalates to 2000, so if we do the same, then it becomes about 33. You also said you only asked gold server, which means you can't have an accurate chunk because you only asked a select few people from the server that's less financially supported, which makes sense that less people would use something that costs so much, you also would have to clarify how often usage for it is, if they used it once in their lifetime does it count as them using it? or does it have to be consistent usage for you to include it in the count. We also don't know what type of players your evaluated chunk includes, is it PvPers, farmers, people that just do leveling for others, etc. because in that regard there would be more variety in the answers if you only ask people that don't do leveling, or that only do leveling
But, by your math only about 33 people on both gold and silver would use that nurse joy, which just seems incredibly inaccurate, and i feel like there's a way for @Walrosskastanie to develop a counter to see it's usage, that could provide a much clearer number.