League scoring has been 6 goals per game over the past four years. In the 1980's, it was a shade over 8.There were a dozen teams that scored 300+ goals a year in the 80s, and a few that topped 400 goals. League-wide, teams averaged close to 4 G/gm through the 80s, and today that's more like 2.5-2.7 G/gm.
League scoring has not been in your range since 2004. It was only above 3.75 goals/per team/per game ("close to 4") from 1981 to 1986.