Adger Corporation is a service company that measures its output based on the number of customers served. The company provided the following fixed and variable cost estimates that it uses for budgeting purposes and the actual results for May as shown below: When preparing its planning budget the company estimated that it would serve 35 customers per month; however, during May the company actually served 40 customers. What activity variance would Adger report in May with respect to its revenue? (Indicate the effect of each variance by selecting for favorable, "U" for unfavorable, and "None" for no effect (i.e., zero variance). Input all amounts as positive values.)