On July 1, 2006, and annually on July 1 thereafter, each hospital shall file with the Office an estimate of the percentage increase in the hospital's gross revenue due to any price increase for charges for patient services during the 12-month period beginning with the effective date of the previous charge description master filed with the Office. The estimate shall include the estimate calculation and supporting documentation in one of the following electronic file formats: Microsoft Excel (.xls) or Comma Separated Value (.csv). Hardcopy documents are not acceptable.