proc format;
   value agefmt (multilabel notsorted)
         15 - 29 = 'Below 30 years'
         30 - 50 = 'Between 30 and 50'
       51 - high = 'Over 50 years'
         15 - 19 = '15 to 19'
         20 - 25 = '20 to 25'
         25 - 39 = '25 to 39'
         40 - 55 = '40 to 55'
       56 - high = '56 and above';
run;