I have definately seen a big difference between clinics. I was told the same thing that Sonia said... they have different predicted outcomes in different areas. Both my daughter's changed quite dramatically when we moved at various times. For instance, my youngest daughter, Kacie was always in the 135% range when we lived in MN, when we moved to San Antonio she jumped to a whopping 172% and now that we are being seen in Fort Worth hers runs in the 120's. My older daugher did pretty much the same thing (different numbers, but the same trend with the up and down thing).