Based on your survey of number of units and sale prices per unit, multi- unit properties with between 5 and 15 units typically offer similar operating efficiencies. However, properties of 16+ units are required to maintain an on-site property manager. The cost of an on-site manager is $800 per unit per year. As this expense is expected to continue indefinitely, it is valued using a perpetuity model at a 5.00% capitalization rate. The subject property is an apartment complex with 17 units. Comparable Sale 1 has 14 units and sold at $320,000 per unit. What is the percentage adjustment? (Be sure to include a positive or negative sign)