I am working a project where I have to come up with some trend in the hedging products use by various Indian companies. I am reading their annual reports and trying to calculate the percentage to which the firms are hedged. But I am finding my approach full of loopholes. 
I am taking outstanding derivatives notional as the hedge and the Foreign currncy borrowings (at Floating international interest rates like LIBOR) and Foreign currency earnings and expenditure. I am facing problems like:
1) Outstanding derivatives data isn't available for all companies.
2) Should I take Foreign currency long term borrowings only or current maturities and short term borrowings too?
3) Is the foreign currency earnings and expenditure a right indicator of it's trade receivables and payables exposed to foreign currency risk?
4) Should I net these Earnings and expenditure or add them?
5) Many a times firms have mentioned unhedged exposures. In that case, I am subtracting the unhedged exposure from Net exposure(Sum of FC borrowings, earning and expenditure) to reach to the hedged or (Outstanding derivatives notional)
6) Also, I am highly confused with some companies who haven't mentioned if the contracts are outstanding notional or fair/carrying value. In that case what to do?
7) Am i doing the right thing by considering all fair value, not designated as hedge etc. items together?
8) Also, Please give any more suggestions or ways in which I should approach this task. 
Thanks a lot in advance.