The PICTURE statement creates the NOZEROS. format. NOZEROS. is explained in Building a Picture Format: Step by Step .
   picture nozeros
              low   -     -1  =  '00.00' (prefix='-'          )
               -1  <-<     0  =     '99' (prefix='-.' mult=100)
                0   -<     1  =     '99' (prefix='.'  mult=100)
                1   -   high  =  '00.00';
run;