https://www.nbcnews.com/better/health/how-often-do-happiest-couples-have-sex-it-s-less-ncna828491
Once a week or so is the average. I'm at about the same amount of time in a relationship as you and we're about once a week. Personally I feel like sex is nice but it takes time and effort and I'm not always in the mood to spend time pleasing someone else (and I'm not going to initiate unless I'm willing to do that). I could see myself having sex a little bit more often if I had a better work-life balance where I felt less pressed for time. This gets me thinking that I should check in with my partner about this topic though!
As someone with a background in linguistics, my jimmies are indeed rustled.