Every appraiser should know how to calculate appreciation or depreciation. Of course, it's all about the quality and quantity of the data for successful results. Calculating market conditions has become one of the most critical adjustments appraisers make. Below we will learn how to calculate market changes with the 1004 MC form. Although FNMA retired this form, many clients and GSEs still require it. The 1004 MC form is a great starting point for your journey to developing a credible result with your data.