(b) (1) The deduction allowed under subsection (a) of this section shall be calculated:

(i) from the first day of commitment to the custody of the Commissioner through the last day of the inmate’s term of confinement;

(ii) except as provided in paragraph (2) of this subsection, at the rate of 10 days for each calendar month; and

(iii) on a prorated basis for any portion of a calendar month.

(2) If an inmate’s term of confinement includes a consecutive or concurrent sentence for a crime of violence as defined in § 14-101 of the Criminal Law Article or a crime of manufacturing, distributing, dispensing, or possessing a controlled dangerous substance in violation of § 5-612 or § 5-613 of the Criminal Law Article, the deduction described in subsection (a) of this section shall be calculated at the rate of 5 days for each calendar month.

(c) A deduction under this section may not be allowed for a period during which an inmate does not receive credit for service of the inmate’s term of confinement, including a period:

(1) during which the inmate’s sentence is stayed;

(2) during which the inmate is not in the custody of the Commissioner because of escape; or

(3) for which the Maryland Parole Commission has declined to grant credit after revocation of parole or mandatory supervision.