Because 12 is followed by three blanks (or three other values that you are not interested in), numeric fields are right-aligned, so you get the final two blanks (or other values) in your WS-SCHED-DEC.
If you always have two decimal places, the easiest thing to do is to change it to PIC XX, which will left-align. If you can have one, or zero, decimal places occupied, so will need to set the PIC XX field to space before the UNSTRING (consult the manual for why) and then change the one or two blanks to zero by your site's preferred method.
If you delimit also by space, you will have a hard time with it. If you always have two decimal places and you know the value which delimits the decimal places (space?) then you'd be OK with specifying two delimiters.