I don’t think the Hall has ever inducted fewer than five inductees for performers and I believe they see five as their minusThere have been more than five inductees over the years, especially in the early years, when the Hall was trying to get all the obvious acts in.
However, the Hall recently expanded the number of nominated acts from ten to fifteen. Expanding the ballot makes it less likely that more than five acts will meet the ballot threshold.
Other things to consider:
-There are other categories. For example, Sister Rosetta Tharpe got in. as an “Early Influence” a few years ago and Nile Rogers was inducted with the relatively-recent category: “Award For Musical Excellence”, which covers people who have worn a lot of musical hats but might not have enough to get in as a solo performer (Ringo Starr, Leon Russell)
-The Hall has always had an expansive view of what can be considered rock and roll. Remember, it started as Jann Wenner’s baby, and Rolling Stone has always been pretty inclusive.
-Groups aren’t eligible until 25 years after their first record (1994).
-Not sure who’s in? Sortable list here
-Not sure who’s not in? Not In Hall of Fame Ranked List
This list has…
Radiohead at #1
Kraftwerk at #2
Roxy Music at #5
MC5 at #6
The Cure at #11
Todd Rundgren at #13
Janet Jackson at #18
Def Leppard at #41
Rage Against the Machine at #47
Devo at #84
The Zombies at #85
LL Cool J at #88
Not going further.
-The Hall has a playlist for all of the nominees at their website.