Test-age chart

I’m posting this here because you can’t post pics in the Training/Nutrition Forum.

Since test levels have such a huge range (300-1000) and the range is pretty much the same after age 20 and we all know that test levels decline with age, I tried to took for more specific data.

I came across this chart but is from one of those scam product websites.

Could this chart be right? I found that to covert from pmol/l to ng/dl, divide by 12.87. That means the peak on the chart is 31 ng/dl???

Could one of you more scientific -types enlighten me? Does anyone have a link to a better chart?

Anybody know?