I found my way to this page from hockeydb.com: http://www.hockeydb....eagues/141.html
From 1942 to 1967 (25 years) the NHL had 6 teams, then expanded to 12 teams in 1967. This is the longest streak the NHL went so far without an expansion.
Then from 1979 to 1991 (12 years) the NHL had 21 teams, then expanded to 22 teams in 1991.
As of the end of this season, the NHL will have gone 12 years again without expanding.
These 3 eras are the longest streaks the NHL has gone without expansion.
I find this to be some interesting information, rather it means anything or not. Although I'm sure the NHL management isn't looking at this information and saying "Hey, we've got to do something about this, guys!"
I wonder if the lockouts we've gone through have had any impact on expansion talks.