olumn  1: V is L[GT=MONTH_IRREG]
 Column  2: TBOXLO is TBOXLO (axis MONTH_IRREG1)
 Column  3: TBOXHI is TBOXHI (axis MONTH_IRREG1)
 Column  4: TBOX is TBOX (axis MONTH_IRREG1)
                         V TBOXLO TBOXHI   TBOX 
16-JAN      12 /  1:   1.00    0.0   31.0  31.00
15-FEB      02 /  2:   2.00   31.0   59.2  28.24
15-MAR      17 /  3:   3.00   59.2   90.2  31.00
15-APR      05 /  4:   4.00   90.2  120.2  30.00
15-MAY      17 /  5:   5.00  120.2  151.2  31.00
15-JUN      05 /  6:   6.00  151.2  181.2 