The value of tmnxOamTrHopsInTtHCSumSqrs indicates the sum of squares of
the inbound one-way trip times of the trace route test for this hop.
Its purpose is to enable the standard deviation calculation.
The value of this object will be reported as 0 when one or more of the
following conditions apply:
1. No inbound one-way trip time measurement is available.
2. The test stopped before completion.
3. The test type (i.e. tmnxOamTrCtlTestMode) is one of the following:
'ldpTreeTrace',
'mcastTraceRoute',
'p2mpLspTrace'.