(1) Notwithstanding any other provision of law to the contrary, any person who is convicted of an offense under section 707-701.5, 707-702, 707-730, 707-731, 707-732, 707-733.6, 707-750, 708-840, 712-1202, 712-1203, or 712-1209.1, after having been convicted on at least three prior and separate occasions of an offense under section 707-701.5, 707-702, 707-710, 707-711, 707‑730, 707-731, 707-732, 707-733.6, 707-750, 708-840, 712-1202, 712-1203, or 712-1209.1, or of an offense under federal law or the laws of another state that is comparable to an offense under section 707-701.5, 707-702, 707-710, 707-711, 707-730, 707-731, 707-732, 707-733.6, 707-750, 708-840, 712-1202, 712-1203, or 712-1209.1, shall be sentenced to an extended term of imprisonment as provided in section 706-661.
(2) A conviction shall not be considered a prior offense unless the conviction occurred within the following time periods:
(a) For an offense under section 707-701.5, 707-702, 707‑730, 707-733.6, 707-750, 708-840, 712-1202, 712-1203, or 712-1209.1, within the past twenty years from the date of the instant offense;
(b) For an offense under section 707-710 or 707-731, within the past ten years from the date of the instant offense;
(c) For an offense under section 707-711 or 707-732, within the past five years from the date of the instant offense; or
(d) For an offense under federal law or the laws of another state that is comparable to an offense under section 707-701.5, 707-702, 707-710, 707-711, 707-730, 707-731, 707-732, 707-733.6, 707-750, 708-840, 712-1202, 712-1203, or 712-1209.1, within the maximum term of imprisonment possible under the appropriate jurisdiction.