The majority in that statistic are selectable 4WD, which isn't the same as AWD. Pushing the two groups together skews the numbers a bit. Most trucks since the 1970s have been 4WD, ever since companies like Muncie and Borg-Warner started selling axles to Ford and their cohorts. AWD trucks are a relatively new phenomenon, with the first one I can think of being the limited production GMC Syclone in 1989, and it being a truck was an emissions loophole. I think the 2005 Honda Ridgeline was the first real mass produced AWD truck, or perhaps the Subaru Baja from 2003 if you consider that a truck rather than an open deck car. Right now I think only the Ridgeline, Hyundai Santa Cruz, and Ford Maverick are sold as AWD, whereas every other truck is selectable 4WD.