This is what I have been able to come up with so far
It is not very detailed — well, the error chart is detailed enough to find all your 500 HTTP errors reported there, the usage you can guesstimate.
An obvious workaround is to set up your home or small office proxy http server to monitor the traffic, then you count occurrences of proxied requests by whatever time period you choose in your proxy server weblog. Another way of saying, we can with relative ease count them ourselves.