"Requests Per Interval" should be a Performance metric, per the following FAQ:
CA APM for Web Servers FAQs - CA Application Performance Management - 9.6 - CA Technologies Documentation
Q. I have a new web server that is not yet available for access to anyone but the CA APM for Web Servers agent. I enabled performance metrics and for metrics such as Requests per Interval, or NotFoundErrors, I see some constant values. Is this behavior normal?
A. Yes, it is normal. To get the performance metrics from a web server, we establish a connection with the server at a defined frequency. This results in some of those metrics with values.