you can not find the exact answer to that question. because, currently, Bitcoin has not been anyone to manage, so, the miners do not need to declare information or register to do business. Everything they are not public, so we can not check and know the exact number. only a few countries in all mandatory taxes, so that only those countries recently launched accurate information
This is true and even though there are regulated mining operations but still there are farms that have not yet been considered or known thats why we cant really put an exact number on how many miners globally. Those charts posted above arent accurate enough to tell since its just an estimate.