How to clear all subscripted variables?

Question

I have the following variable:

Subscript[n, 0 ] = 12 (\[Sigma] L^2)/(e h^2)

If I now do:

ClearAll["Global`*"]

And then call:

Subscript[n, 0 ]

I get:

12 (\[Sigma] L^2)/(e h^2)

... So apparently a variable with a subscript cannot be deleted by "clear all".

How can you do it ?

Here for testing:

Subscript[n, 0 ] =12 (\[Sigma] L^2)/(e h^2)
ClearAll["Global`*"]
Subscript[n, 0 ]