Note that although the last observation contains values for START and END, these values are ignored because of the O value in the HLO variable. 

                               The CTRL Data Set                               1

         label          start    end        fmtname         type    hlo

         0%              0       3      PercentageFormat     n         
         3%              4       6      PercentageFormat     n         
         6%              7       8      PercentageFormat     n         
         8%              9       10     PercentageFormat     n         
         10%             11      16     PercentageFormat     n         
         ***ERROR***     11      16     PercentageFormat     n       O