Early to mid 80s seemed to be dominated by Brian Meehl; mid to late 80s seemed to be dominated by Richard Hunt and Kevin Clash (and Marty Robinson to a lesser extent).
Yes, this trend is visible throughout the entire show's history.
1969-1979: Jim Henson, Frank Oz, and Caroll Spinney kicked things off for the first year; then Jerry Nelson and Richard Hunt joined in the early 1970s. Fran Brill was hired in 1970 and did recurring characters like Prairie Dawn.
1980-1984: Jim and Frank start to ease up from their SS duties, and Brian Meehl and Marty Robinson join the company to perform Snuffy.
1985-1990: Richard Hunt and Jerry Nelson's characters appear more frequently, and Kevin Clash starts performing Elmo. Jim Henson performs in more inserts as Kermit, Ernie, Guy Smiley, and Bip Bipadotta until his sudden passing in 1990.
1991-1999: Richard Hunt dies in 1992, and David Rudman becomes a key part of the cast as Baby Bear.
2000-2012: Kevin, David, and Marty carry the torch. Eric Jacobson, Matt Vogel, and Leslie Carrarra-Rudolph become mainstays as well. Caroll, Fran, Jerry, and Frank continue to perform thirty years after they began on Sesame.
2012-present: after Jerry's death, Matt inherits the Count (and Big Bird after Caroll's 2019 passing). Eric becomes the full-time performer of Grover, Bert, and Oscar. Peter Linz gains recognition for his performances as Ernie beginning in the mid-2010s. Stacy Gordon plays Julia, a character with autism.