It is very clear that we cannot find how many wallets are opened so far and how many people are using bitcoin as each transaction are having mostly unique wallet address as almost all wallets are generating new address as soon as the old address is used in any transaction. But even if you find the number of wallets opened then also you cannot find the number of peoples using bitcoin as their are users who are using multiple wallets for bitcoin.

So it is very clear that nothing can be done for your query.