Esperanto has way way more speakers than Klingon. "Arika Okrent guessed in her book In the Land of Invented Languages that there might be 20–30 fluent [Klingon

Esperanto has way way more speakers than Klingon. "Arika Okrent guessed in her book In the Land of Invented Languages that there might be 20–30 fluent [Klingon] speakers."[1] "In 2009 Lu Wunsch-Rolshoven used 2001 year census data from Hungary and Lithuania as a base for an estimate, resulting in approximately 160,000 to 300,000 to speak [Esperanto] actively or fluently throughout the world, with about 80,000 to 150,000 of these being in the European Union."[2] "As of 1996, there were 350 or so attested cases of families with native Esperanto speakers. Estimates from associations indicate that there are currently around 1,000 Esperanto-speaking families, involving perhaps 2,000 children. In all known cases, speakers are natively bilingual, or multilingual, raised in both Esperanto and either the local national language or the native language of their parents."[3] [1]: https://en.wikipedia.org/wiki/Klingon_language#Speakers https://en.wikipedia.org/wiki/Klingon_language#Speakers [2]: https://en.wikipedia.org/wiki/Esperanto#Number_of_speakers https://en.wikipedia.org/wiki/Esperanto#Number_of_speakers [3]: https://en.wikipedia.org/wiki/Native_Esperanto_speakers https://en.wikipedia.org/wiki/Native_Esperanto_speakers