#charge_per_unit__rate  amount of a charge or payment relative to some basis; "a 10-minute phone call at that rate would cost $5"
  supertype:  charge  the price charged for some article or service; "the admission charge"
  subtype:  pay_rate__payrate__rate_of_pay  amount of money received per unit time; "women's pay rate is lower than men's"
     subtype:  time_and_a_half  a rate of pay that is 1.5 times the regular rate; for overtime work
  subtype:  payment_rate__paymentrate__rate_of_payment__repayment_rate__repaymentrate__installment_rate__installmentrate  the amount of money paid out per unit time
  subtype:  tax_rate__taxrate  rate used to calculate tax liability
  subtype:  interest_rate__rate_of_interest  the percentage of a sum of money charged for its use
     subtype:  discount__discount_rate__bank_discount  interest on an annual basis deducted in advance on a loan
        subtype:  bank_rate  the discount rate fixed by a central bank
     subtype:  discount_rate  (US) the rate of interest set by the Federal Reserve that member banks are charged when they borrow money through the Federal Reserve System
     subtype:  prime_interest_rate  the interest rate on short-term loans that banks charge their commercial customers with high credit ratings
     subtype:  vigorish__usury  an exorbitant or unlawful rate of interest
  subtype:  freight_rate__freightrate__freight__freightage  the charge for transporting something by common carrier; "we pay the freight," or "the freight rate is usually cheaper"
  subtype:  rate_of_depreciation__depreciation_rate  the rate at which the value of property is reduced; used to calculate tax deduction
  subtype:  rate_of_exchange__exchange_rate  the charge for exchanging currency of one country for currency of another
  subtype:  excursion_rate__excursionrate  a reduced rate for a round-trip ticket
  subtype:  footage.charge_per_unit  a rate of charging by the linear foot of work done
  subtype:  linage__lineage  a rate of payment for written material that is measured according to the number of lines submitted
  subtype:  room_rate  the rate charged daily for a hotel room

No statement uses or specializes charge_per_unit; click here to add one.