I was able to find that as of August 2019 the Pokemon TCG has sold a total of 27.2 billion cards worldwide. (link:株式会社ポケモン | The Pokémon Company株式会社ポケモン|The Pokémon Company)
But I’m very curious to see how Pokemon cards have sold on a year-to-year basis? Any chance someone knows if it’s possible to find such data?
(And if there is no precise data, then how would you compare the popularity of the Pokemon TCG today compared to what it’s been in years past?)