The total number of events read in this sampled report for a date range.
This is the size of the subset this property's data that was analyzed in
this report.
The total number of events present in this property's data that could
have been analyzed in this report for a date range. Sampling
uncovers the meaningful information about the larger data set, and this
is the size of the larger data set.
To calculate the percentage of available data that was used in this
report, compute samplesReadCount/samplingSpaceSize.