The number of previous 15 minute intervals for which valid data was collected. The value will be 96 unless the IMA group table entry was created within the last 24 hours, in which case the value will be the number of complete 15 minute intervals since the IMA group table entry was created. In the case where the agent is a proxy, it is possible that some intervals are unavailable. In this case, this value is the maximum interval number for which valid data is available. This attribute is only mandatory when the IMA Link Interval Statistics and/or IMA Link Total Statistics objects are implemented.