Streaming services may implement bandwidth throttling to manage network traffic during peak and off-peak hours, ensuring consistent service quality. The function $f(t) = 160 + 42\cos(0.2618t)$ models the bandwidth availability (in Mbps) for a streaming service over time, where $t$ is measured in minutes within a 24-hour cycle. Find the rate of change in bandwidth availability when $t = 17$ hours. Write only a number as your answer and round to one decimal place.
