I am looking for data on elapsed time from proposal of new or amended federal (U.S.) regulations until publication date and effective data of final rules.

This may only apply to regulations which proceed through the "normal" rulemaking process, not to regulations adopted without notice or comment under the "good cause" exception; direct, final rulemaking; final rules adopted after the publication of interim final rules; or rules developed through negotiated rulemaking.

I have not located related research through data base searches, although I may not be phrasing the search terms optimally. I have located an immense body of somewhat related research, but not any which speaks specifically to how long the rulemaking process takes.