This is a 64-bit counter, accumulated since the last reboot, of connection attempts for the specific protocol denoted by cufwConnProtocol that were declined due to security policy. An admin uses this per-protocol figure to identify exactly which protocol's traffic is being blocked by policy, rather than only knowing that policy declines are happening somewhere on the firewall. For example, if this counter is high only for the row corresponding to a particular protocol, the admin would go check the access rules governing that specific protocol.