Any changes in accounting methods and practices or in statutes affecting expenditures or revenues for the ensuing biennium relative to the then current fiscal period which the governor may wish to recommend shall be clearly and completely explained in the text of the budget document, in a special appendix thereto, or in an alternative budget document. This explanatory material shall include, but need not be limited to, estimates of revenues and expenditures based on the same accounting practices and methods and existing statutes relating to revenues and expenditure effective for the then current fiscal period, together with alternative estimates required by any changes in accounting methods and practices and by any statutory changes the governor may wish to recommend.