I find that these diagrams are hot and clear.

The graph is actually easy to read and quite clear.

What I want to know is who goes to rehab for marijuana?!?! Its not a physically addictive substance. When you quit you get a little restlessness for a couple of weeks and thats about it. No sweats, no sickness, no nothing. I know people who smoked everyday for 15 years (and got PhDs and graduated with honors while they did it) and then one day said "ehh, thats enough, I'm tired of smoking" and that was it, no rehab! Sure its an emotional habit but come on!

The graph is problematic because (a) it invites the reader to make a lot of comparisons (across sexes, across time, across drugs, and across races) and is overwhelming; and (b) a lot of these comparisons are not appropriate because the graph is referring to counts, not rates (e.g. you can't say whites are more likely to wind up in rehab because there are just more white people in the population). Because the number of people in each sex and race group differ, the only proper comparison you can make is across drugs for the same time period, same gender, and same racial group.