Ontario Health Areas
  (N.B. used only in Ontario Health Survey)
   
  Source: Ontario health survey, 1996-1997: derived variables technical 
    documentation. 
  <http://prod.library.utoronto.ca/datalib/codebooks/utm/ohs/1996_97/ohs97dervar.pdf>
  
  Ontario health areas, 1994
  
  51 - East
  52 - Central East
  53 - Central West
  54 - Southwest
  55 - Northeastern & Northwestern
  96 - Not Applicable
  
  
  Ontario health areas, 1996
  
  3511 = Ottawa Carleton
  3512 = Prescott, Russell, Stormont, Dundas, Glengarry, Renfrew
  3513 = Lanark, Leeds, Grenville, Hastings, Prince Edward, Frontenac, Lennox a d Addington
  3521 = Northumberland, Victoria, Haliburton, Peterborough
  3522 = Durham
  3523 = Peel
  3524 = Metro Toronto
  3525 = York
  3526 = Simcoe
  3527 = Halton
  3531 = Niagara
  3532 = Hamilton-Wentworth
  3533 = Brant, Haldiman, Norfolk
  3534 = Wellington, Dufferin
  3536 = Waterloo
  3541 = Essex
  3542 = Lambton, Kent
  3543 = Elgin, Middlesex, Oxford
  3544 = Bruce, Grey, Perth, Huron
  3551 = Algoma, Cochrane
  3552 = Manitoulin, Sudbury
  3553 = Timiskaming, Muskoka, Parry Sound, Nipissing
  3561 = Thunder Bay, Kenora, Rainy River