I suggest to add a guideline or standard operation procedure for fee adjustment to make the committee members life easier and the community know how the fee adjustment work.
For example:
Time interval: Fee will be adjusted on the first day of every month (so community know when it will happen).
Reference Price: Average price of BTS/USD for Last 3 days or last 30 days from CMC or price feed (so community know where is the price come from).
List of current fee in USD.
If community want to appeal a particular fee eg account creation fee, he or she may open an issue and discuss with committee members.
I suggest to add a guideline or standard operation procedure for fee adjustment to make the committee members life easier and the community know how the fee adjustment work.
For example: