> stem(x, par1, par2, par3)
  The decimal point is at the |
   7 | 0
   8 | 
   9 | 0
  10 | 
  11 | 0
  12 | 
  13 | 00
  14 | 00
  15 | 00000
  16 | 0000000000
  17 | 00000000
  18 | 00000000000000
  19 | 000000000000
  20 | 0000000000000000000
  21 | 00000000000000
  22 | 00000000000000000000
  23 | 00000000000000
  24 | 0000000000000000
  25 | 000000000000
  26 | 0000000
  27 | 00
  28 | 00