Adjustments to Volume monitoring

We've made some tweaks to our Volume anomaly detection, making it slightly less sensitive. Users should expect Volume thresholds to widen slightly, with the effect of roughly ~20% fewer Volume alerts.

A few months ago, we rebuilt our Volume anomaly detection, making it dramatically more sensitive. These changes nearly tripled the number of Volume alerts that Monte Carlo sends. The overall reception to these changes has been great, but we've found the default 'Medium' sensitivity to be sending more alerts than is universally desirable. As a result, we've implemented these changes to make it slightly less sensitive.

Users can still benefit from our most sensitive anomaly detection by setting Sensitivity to High.