SGPanel bug?

sgpanelbug.sas

data gnu ;
  input
    @1    var_name  $char20.
    @23   value     $char1.
    @27   enr_end   date9.
    @39   site      $char1.
    @43   pct
  ;
  format
    enr_end mmddyy10.
    pct percent9.0
  ;
datalines ;
outside_utilization   Y   01jan2000   W   .89
outside_utilization   Y   01jan2001   W   .91
outside_utilization   Y   01jan2002   W   .78
outside_utilization   Y   01jan2003   W   1
outside_utilization   Y   01jan2000   N   .8
outside_utilization   Y   01jan2001   N   .77
outside_utilization   Y   01jan2002   N   .78
outside_utilization   Y   01jan2003   N   .95
outside_utilization   Y   01jan2000   S   .72
outside_utilization   Y   01jan2001   S   .8
outside_utilization   Y   01jan2002   S   .43
outside_utilization   Y   01jan2003   S   .67
outside_utilization   N   01jan2000   W   .9
outside_utilization   N   01jan2001   W   .09
outside_utilization   N   01jan2002   W   .22
outside_utilization   N   01jan2003   W   0
outside_utilization   N   01jan2000   S   .28
outside_utilization   N   01jan2001   S   .2
outside_utilization   N   01jan2002   S   .57
outside_utilization   N   01jan2003   S   .67
run ;

proc format ;
  value $s
    'N' = 'North'
    'S' = 'South'
    'W' = 'West'
  ;
quit ;

 ods html path   = "c:\temp" (URL=NONE)
          body   = "deleteme.html"
          (title = "deleteme output")
           ;

  proc sgpanel data = gnu ;
    panelby var_name value ;
    loess x = enr_end y = pct / group = site ;
    rowaxis grid ;
    format enr_end year4. site $s. ;
  run ;

 ods _all_ close ;