Excel export,

I am trying to calculate the total of CPU utilization for a given time, but
I received all zero after using pivot table. The source data looks like below:

TIME USER %CPU SZ VSZ

2007/09/18 00:14:15 oracle 0.02 25360 102464
2007/09/18 00:14:15 oracle 0.98 25488 102976
2007/09/18 00:14:15 root 0.02 86 408
2007/09/18 00:14:15 root 1.50 4832 19328
2007/09/18 00:14:15 root 0.02 56 232
2007/09/18 00:14:15 oracle 80.38 25552 103488
2007/09/18 00:16:16 oracle 0.81 25488 102976
2007/09/18 00:16:16 root 0.28 52 228
2007/09/18 00:16:16 oracle 5.21 25232 100928
2007/09/18 00:16:16 oracle 0.94 25488 102976
2007/09/18 00:16:16 oracle 0.78 25488 102976
2007/09/18 00:16:16 oracle 0.94 25488 102976
2007/09/18 00:16:16 oracle 0.91 25488 102976
2007/09/18 00:16:16 oracle 0.89 25488 102976

Can anyone give me some hints where is wrong? Thanks a lot.

--Ying