I'm having a hard time understanding the scale of that graph. Benzos are a 1.75 but cannabis is a 1.5 in regards to dependence? Amphetamines (Adderall) are 1.

I'm having a hard time understanding the scale of that graph. Benzos are a 1.75 but cannabis is a 1.5 in regards to dependence? Amphetamines (Adderall) are 1.75 in regards to physical harm, but anabolic steroids are only 1.5?