Wis. Stat. § 625.34

Recording and reporting of experience. The commissioner shall promulgate or approve reasonable rules, including rules providing statistical plans, for use thereafter by all insurers in the recording and reporting of loss and expense experience, in order that the experience of such insurers may be made available to the commissioner. No insurer shall be required to record or report its experience on a classification basis inconsistent with its own rating system. The commissioner may designate one or more rate service organizations to assist the commissioner in gathering such experience and making compilations thereof, which shall be made available to the public.