Provision for doubtful debts is subtracted from debtors while calculating current ratio but not in debtors turnover ratio.why?

Provision on Debtors is always deducted while computing any of the Ratios as the fundamental accounting concept says that ratios shall always be calculated on Good Debtors i.e. Debtors less Provisions.
This is because Schedule III only depicts the presentation of different items in the Balance Sheet of a company. It no where highlights the change in accounting practices/ concepts. Accordingly, While calculating Current Asset Ratio/Total Asset Turnover Ratio or Proprietary Ratio, it should be deducted from amount of debtors. 

However, deduction of provision for bad debts from debtors is not done or may be added to net debtors so as to provide with more accurate results of Debtors Turnover Ratio, i.e. Net credit sales to gross debtors signifying the relationship between actual credit sales and actual amount receivable.