It shows surprise as earnings increased by 100% (6,4)
I believe the answer is:
double take
'it shows surprise' is the definition.
The definition suggests a singular noun which matches the answer.
'earnings increased by 100%' is the wordplay.
I cannot quite understand how this works, but
'earnings' could be 'take' (I've seen this in another clue) and 'take' is found in the answer.
The remaining letters 'double' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'as' is the link.
Can you help me to learn more?
(Other definitions for double take that I've seen before include "Delayed action" , "Second reaction to the unexpected" .)