The answer is mathematics. This is a chart based on country of origin. Yes, there are loads of Latin American women authors who are great, but they’re spread around more than a dozen South & Central American countries, so no one Latin American country ranks very highly.

If you did another graph based just by language, Spanish would almost certainly outrank Swedish (a no-brainer, since Sweden has just a little more than 20 books more than Spain. But Spanish might also get surprisingly close to French.