Premium rates for a health benefit plan issued or renewed to an individual, a small group, or an association on or after April 10, 1998, shall be subject to the following provision: the premium rates charged during a rating period to an individual with similar case characteristics for the same coverage, or the rates that could be charged to that individual under the rating system for that class of business, shall not vary from the index rate by more than 35% of the index rate upon any policy issuance or renewal, on or after January 1, 2003.