Clarinet condensing standard

[NeeraWM]

I have browsed enough scores from the XIX century symphonic repertoire to see that, while Flute, Oboe, and Bassoon (and all brasses) were more often than not condensed, the Clarinets were not.
Can anyone explain why this happened and when this habit got abandoned?
For example: both Clara and Robert Schumann piano concerto's first editions have uncondensed clarinets; Tchaikovsky's 5th symphony has them condensed. Sometime in between things must have changed, and I wonder what lead to the change.
Thank you!

[hautbois baryton]

It probably depends on context and how active the parts are compared to one another. Clarinet 1 could be doing something in upper register while Clarinet 2 is doing something completely different in the chalumeau register.

[NeeraWM]

Flute, Oboe, Bassoon are always condensed even when doing completely different things.
Clarinets always decondensed even when play the same rhythm at different intervals or even when playing 'a 2'.

[MichelRE]

I don't know if it really was an original manuscript, but the Clara Schumann piano concerto "manuscript" score I looked at had absolutely no condensing at all, no flutes, oboes, bassoon, horns, nothing.

[NeeraWM]

Sorry for the confusion, I meant the first Breitkopf edition (1980 ca.)

[Callasmaniac]

SomeTsaikovski scores have un-condensed flutes parts when all other woodwinds are condensed...Odd.