After two years in your first job, you are promoted to call center manager for a major hotel chain. The expected service rate is 3.0 minutes per telephone call per customer service representative (CSR). With three telephone CSRs on-duty during the 6:30 to 7:00 a.m. time period, and assuming a 90 percent target CSR labor utilization rate, how many telephone calls can these three CSRs handle during this time period?