P1‐565: ESTIMATING THE FUTURE PREVALENCE OF DEMENTIA IN CANADA: AN INTERNAL VALIDATION OF SHORT‐TERM PROJECTION METHODS USING ADMINISTRATIVE HEALTH DATA. (1st July 2019) - Pelletier, Catherine; Gao, Yong Jun; Zakaria, Dianne; Bartholomew, Sharon; Demers, Alain; O'Donnell, Siobhan; Robitaille, Cynthia; Robert, Anne-Marie; Toews, Jennette