The median length of albums on the list is 43 mins.
50% of albums run between 38 mins and 52 mins.
This changes over time - below is the median length for each decade:
The increase from 39 mins in the 50s - 70s to 53 mins in the 90s - 00s was due to the rise of the CD as the dominant medium.
Did creativity change such that everyone had an extra 14 mins of juice in the tank? No.
Were artists constrained by the limitation of vinyl? Not in a way that impacted the quality of their output.
Albums got longer because there was more space available. The curse of the CD.
Does anyone feel ripped of buying a classic album that is only 40 mins long? No. (Sure we'd like to hear more, but thats different.)
Is anyone totally over a not so classic CD that runs over 60 mins? Yes - give me less and make it better.
Tip for artists: Make your next opus "short" enough to fit on a single vinyl LP - it didn't hurt most of the artists on this list and may enhance the quality of the finished product.