Bartosiewicz Clinic uses client-visits as its measure of activity. During January, the clinic budgeted for 3,100 client-visits, but its actual level of activity was 3,080 client-visits. The clinic has provided the following data concerning the formulas used in its budgeting and its actual results for January: Data used in budgeting: Fixed element per month Variable element per client-visit Revenue - $ 35.10 Personnel expenses $ 27,100 $ 11.10 Medical supplies 1,100 5.10 Occupancy expenses 10,100 1.00 Administrative expenses 6,100 0.20 Total expenses $ 44,400 $ 17.40 Actual results for January: Revenue $ 124,660 Personnel expenses $ 72,010 Medical supplies $ 22,702 Occupancy expenses $ 14,610 Administrative expenses $ 8,115 The activity variance for net operating income in January would be closest to: