And here's an explanation of what each of the columns means. Hits is the total number of times that serverMonitor has attempted to contact the server. Errors is the number of consecutive errors, in real-time. As soon as a message gets thru, this is reset to zero. When its non-zero, the name of the server displays in red, so you can't miss it.
Reliability is the percentage of messages that worked.
A high-90s percentage probably isn't a problem. No matter what, it's giving you a good idea of what percentage of user requests to the server are actually happening. Net bandwidth contributes to a high number, as does load on the server. Last error message is sticky. This gives you some way of having a clue as to what's going wrong on the server in question, even if you weren't watching when the error happened.