[ComputerGroupid] | [Computerid] | [Userid] | [loginTime] | [logoffTime]
 A                 | 1            | 1        | 09:00       | 10:00
 A                 | 2            | 2        | 09:01       | 10:01
 A                 | 3            | 3        | 09:02       | 10:04
 A                 | 4            | 4        | 09:03       | 10:03
 A                 | 5            | 5        | 09:10       | 09:15

  [StartTime]  |  [endTime]  |  [numberOfcomputerBeingUsed]
  09:00        |  09:01      |  1
  09:01        |  09:02      |  2
  09:02        |  09:03      |  3
  09:03        |  09:04      |  4
  09:10        |  09:15      |  5
  09:15        |  10:00      |  4
  10:00        |  10:01      |  3
  10:01        |  10:02      |  2
  10:02        |  10:03      |  1
  10:03        |  10:04      |  0