I typed up every Jedi name into a Notepad document (1 on each line), then I used a sorting program to sort them alphabetically. After that, I removed duplicates and counted the number of lines in the document, thus giving the number of Jedi. I did the same for the Sith. However, I made some typos when making the lists, and the above numbers are wrong. The actual numbers should be 877 and 386 (notice that the number of Jedi is prime). That's definitely a lot of Force-sensitives, 1,263 to be exact. That's about one Jedi/Sith born every 28 years, over the whole Legends timeline, spanning 36,591 years. No wonder it's hard to remember all those names. I wonder how many people, both Force-sensitive and Force-blind, were born (and died) during that period. I bet it was in the quintillions or even sextillions, given such a long timespan and the present galactic population of about 100 quadrillion (as of 0 ABY).
According to quantum physics, every physically possible universe exists in what's called the Multiverse. This means that the Star Wars galaxy could possibly exist in another, inaccessible universe. I wonder which one...