Open Question: How popular is Brazilian Jiu Jitsu in comparison to Judo?

I’m just wondering how many people do BJJ in relation to those who do Judo. I ask because i noticed that it’s much harder to grade in BJJ than it is in Judo and it seems like there are more blackbelts in Judo than BJJ. I know Judo is a lot more popular but I’m just wondering by how much and is this why there are more blackbelts or is it just because it’s easier to grade
I’m kind of looking for a percentage answer. Like population difference or something. I want to know HOW much more popular