* No Central Database: There's no official registry or tracking system for every Pokemon card ever produced.
* Production Variations: The number of cards produced for each set can vary significantly, and not all cards from a set are equally rare.
* Card Distribution: Cards are distributed globally, making it difficult to account for all of them.
* Card Loss and Damage: Cards get lost, damaged, or destroyed over time.
What we can say:
* Rarity: The Mewtwo Star icon card is a rare card, but not the rarest.
* Value: The value of a card like this depends on its condition, the set it's from, and the demand.
If you want to estimate the number:
* You might be able to find information on online forums or communities dedicated to Pokemon card collecting.
* However, any numbers you find should be taken with a grain of salt, as they're likely based on estimates and speculation.