A computer software firm provides a 20' x 30' office for its six systems analysts and plans to hire two additional analysts. To maintain a 100-square-foot working space per analyst, the firm’s owner-manager is considering expansion. The cost of expansion is $40 per square foot with annual maintenance costs of $4 per square foot. The useful life of floor space is 20 years. By how much should employee productivity increase to justify the additional expenditure? The current salary of the systems analysts is $25,000.