Each jury plan shall set intervals for creation of a prospective juror pool and a qualified juror pool. Each jury plan shall set a minimum number of names to be selected from the source pool as prospective jurors. The minimum number shall be: At least 150; and Except as provided in paragraph (3) of this subsection, at least 0.5% of the total number of names in the source pool. If the minimum percentage under paragraph (2)(ii) of this subsection would be cumbersome and unnecessary, a jury plan may set a smaller number. A jury judge for a county may order its jury commissioner to have additional names selected from the county’s source pool as the judge considers necessary.