How much have modern day manufacturing techniques and materials along with more advanced transducer design and technology increased average speaker sensitivity?

If the average 10" acoustic suspension bookshelf speaker of the 1970's (say small Advent) put out 85-86db SPL with 1 watt input at 1 meter, how much more sensitive would a modern version have for same size cabinet and bass cutoff?

To put it another way, if JBL were to make the best possible version of the original L-100 configuration today, would the sensitivity be higher or the same holding all other parameters the same?

I have sold audio daily since the early 1970's. My estimate is an average industry increase of about 3db.

My guess is that since JBL was always pushing boundaries for high sensitivity, their drivers or speakers have not increased that much. Certainly they have smoother response, lower distortion, greater power handling and wider bandwidth though.