Adhoc allowances have a strong relation to the basic pay. These adhoc relief allowances started from 1994. You can calculate your arrears of allowances connected with the increase in the past pay. Also, you can check your granted back date up-gradation, back date promotion or back date running pay scales and much more. Certainly your basic pay had been increased if you have back date pay fixation and the allowance rates to be increased along with the basic pay.
If you want to know about the rates of allowances that were granted in the past to Govt Employees, then below Chart is valuable for you.