This object indicates the number of intervals for which data
was collected. The value of this column will be '96' unless the
measurement was started (or restarted) within 1,440 minutes, in
which case the value will be the number of complete 15-minute
intervals for which the system has at least some data.
In certain cases it is possible that some intervals are
unavailable, in which case the value of this column will
be maximum interval number for which data is available.