Indiana Small Group Medical Insurance Rate Increases

What is guidelines are in place regarding rate increases for small group medical insurance for the state of Indiana. I presently pay $162.00 every two weeks(for me and my spouse)and just received an increase of an additional $120.00 (which is a rate increase of about 75%) every two weeks. Is this legal and if so what guidelines are in place if any regarding what amount of rate increase an insurance company can apply and how often.

Thank You for Your Review of this Matter.

Brian