I know this one is old, but I had to comment…
In the report, SDSTAFF Dex explains that the reason a cup of coffee has more caffeine than a cup of tea, even though teal leaves contain more caffiene than coffee beans is that caffeine is “more readily extracted” from the coffee beans
While I’m not sure if this is true of not, I do know that to brew an 8Oz cup of coffee, you use about four times the amount of ground beans (10g or so) than you use tea leaves for a cup of tea. (2.5 g )
The higher caffeine content of coffee is obviously due to tha fact that so much more product is used to make the same size serving.