tabulate percentage heck

proc format ;
  value $sx
    "F" = "Girls"
    "M" = "Boys"
  ;
  value ag
    low - 12 = '12 and under'
    13 - high = '13 and up'
  ;
quit ;

%let out_folder = c:/deleteme ;

data shill ;
  length sex $ 5 ;
  set sashelp.class ;
  do teacher = 'Mr. Smith', 'Ms. Jones' ;
    if teacher = 'Ms. Jones' then age = age - 1 ;
    output ;
  end ;
run ;

ods html path = "&out_folder" (URL=NONE)
         body   = "tab_sketch.html"
         (title = "tab_sketch output")
          ;

* rowpctn gives the percentages across the whole row--how do I get percentages within sex? ;
* e.g., what perceentage of the girls in Mr. Smith's class are 12 or younger? ;
proc tabulate data = shill ;
  class teacher sex age ;
  keylabel N = " " sum = " " ;
  var height weight ;
  table teacher, sex=" " * age=" " * (n="N" rowpctn="%") ;
  format sex $sx. age ag. ;
run ;

ods _all_ close ;