I've just had a medical check-up for a job at a petroleum refinery. I think I'm in good health and don't have any breathing issues, but my PFT Test spirometry result graph only reached 6 or 7. From what I read online, it should be above 8. Does this mean I'm not medically fit, or is that a normal result? I'm really worried because my future depends on it. Can you help me understand what this means?