The following is an estimate of the amount of time, in days,
that the PSI valves were open.

The numbers were taken from the PSI monthly trend plots.

Grand Total:  311.2 days

month  days  total
03/96   1.2
04/96   4.6
05/96   2.0
06/96   1.4
07/96   4.0
08/96   7.5
09/96   1.5
10/96   1.0
11/96   0.0
12/96   0.0   23.2

01/97   0.0
02/97   0.0
03/97   7.4
04/97   4.5
05/97   3.3
06/97  10.4
07/97   0.0
08/97  14.0
09/97   0.0
10/97   1.0
11/97  13.2
12/97   0.0   53.8

01/98   7.0
02/98   7.2
03/98  14.1
04/98   1.0
05/98  11.3
06/98   0.0
07/98   9.4
08/98   5.0
09/98   9.2
10/98  10.5
11/98   0.0
12/98   2.5   77.2

01/99   0.0
02/99   3.5
03/99  13.5
04/99  17.8
05/99   3.0
06/99   0.0
07/99  13.5
08/99   0.0
09/99  10.2
10/99   4.5
11/99   0.0
12/99   8.0   74.0

01/00   0.0
02/00  15.0   
03/00   2.0
04/00  13.5
05/00   3.0
06/00   2.2
07/00   6.0
08/00   0.0
09/00  14.5 
10/00   4.2
11/00   0.0
12/00   0.0   60.4

01/01   0.0
02/01   0.0
03/01   3.0
04/01   0.0
05/01   0.0
06/01   0.0
07/01   0.0
08/01   7.5
09/01   0.0
10/01   3.5
11/01   0.0
12/01   0.0   14.0

01/02   0.0
02/02   0.0
03/02   9.6