How much % do steroids raise testosterone levels?
The average male produces between 5–10 mg per day of testosterone naturally - that's about 35–70 mg per week total.
Testosterone Replacement Therapy uses about 100–200 mg of testosterone in weekly injections
Gender re-assignment for Female-to-Male trans-therapy uses about 100 mg of testosterone in weekly injections.
Competitive Professional and Top Amateur Bodybuilders have been known to use up to 1000–2000 mg of testosterone (or more) of anabolic steroids per week, plus Growth Hormones and Insulin to support muscle growth.
I would estimate that MOST competitive non-Bodybuilding/powerlifting/weightlifting athletes who use anabolic steroids will use between 200mg and 500mg weekly.