Spotlight does not store that exact column but do store the in and out separately so user can calculate it. Below is SQL to get the data
declare @t table
insert into @t
@start_date = N'jan 1 2016',
@end_date = N'jan 1 2017',
@monitoredobject_list = N'host1,host2',
@table_name = N'network',
@column_list = N'BytesInPerSec,BytesOutPerSec,Instance'
Select timecollected as [Date], monitored_object_display_name as [Connection], instance as [Network Card], (bytesinpersec + bytesoutpersec) / 1024 as [KB In/Out] from @t
order by timecollected, monitored_object_display_name, instance
**You will need to change the database name in the use statement, the start and end dates and the list of host names (everything in bold).