The growth rate for Frazier Fir is described as "slow" which means 12" or less per year. That is if the tree is growing in its optimal site. Weather, soil, drainage, water, fertility etc.etc. affect the growth. The Frazier Fir does best where the summers are cool and moist. It might not grow the predicted 12" or less per year depending on your summers. You are in Jamison which may be in the mountains of PA and be cooler than in Philadelphia. The tree does well in the mountains of North Carolina.