FIGURE 5: Duration and cost per user and call
username firstminute lastminute duration cost
-------- ----------- ---------- -------- ----
user3 2003-02-04 23:00:00 2003-02-07 22:59:00 4320 162.0000
user2 2003-02-12 23:00:00 2003-02-13 22:59:00 1440 54.0000
user1 2003-02-12 21:30:00 2003-02-12 22:29:00 602.1000