We have a report where you can bench mark with other monitors for availability. To get this report goto report tab > custom report > Global bench mark report. Configure for the monitor group and select availability (in select a metric for comparison). You can then select the locations you want to compare. Once configured you can Save the report.
You will get a report like the one below. Here I am comparing 3 monitor groups in 2 locations.
Would this report suite your need? Let me know.
Product Manager, Site24x7