The Director of Corrections shall fix a daily rate to be expended for convict labor, and when so fixed, the Department of Transportation shall monthly set aside funds to the director to pay for this labor from funds appropriated in the Budget Act for this purpose, and where no funds are available to the Department of Transportation the director may set aside the department’s own funds to pay for this labor from funds appropriated in the Budget Act for this purpose. The Department of Corrections shall set up an account for each convict which shall be credited monthly with an amount computed by multiplying the daily rate by the number of days such convict actually performed labor during the month. Such account shall be debited monthly with the convict’s proportionate share of expenses of camp maintenance, including the expenses for food, medicine, medical attendance, clerical and accounting personnel, and the expenses necessary to maintain care and welfare facilities such as camp hospital for first aid, barbershop and cobbler shop, and the convict’s personal expenses covering his drawings from the commissary for clothing, toilet articles, candy, and other personal items. The charge for camp maintenance may be made at a standard rate determined by the department maintaining the camps to be adequate to cover expenses and shall be adjusted periodically at the discretion of the department as needs of the camp require. No charge shall be made against such account for the costs of transporting prisoners to and from prison and camp or for the expense of guarding prisoners, which items shall be paid by the Department of Corrections from appropriations made for the support of the department. The director, by regulation, may fix the maximum amount, over and above all deductions, that a convict may receive. The Department of Corrections, in computing the debits to be made to the convict’s accounts, may add not to exceed 10 percent on all items.