Thunderbird version

[Thomas Blasejewicz]

Good evening
This is probably is very stupid question, but ...

on my windows machines Thunderbird is now version 68 something.
Under Linux (I use mainly Mint, but is supposed to be based on Ubuntu), 
the version is 60 and the software center tells me, THIS IS the latest 
version.

Searching the net, there is a version 68 .tar.bz2 file to download, but 
everywhere I look, people advice AGAINST installing this and instead use 
the software center.

Is there any particular reason why the software center seems to lacking 
EIGHT versions behind?

Since Thunderbird is working just fine, this is not really any kind of 
"problem", but I still would like to know ...

Thank you
Thomas