I was gonna quote this one for the guy that said 99% :(
“We might see ads declaring that ‘4 out of 5 doctors recommend Brand X,’ but we are rarely told how many doctors were surveyed, how they were chosen, what they were asked, or who sponsored the study. Without such information, we cannot assess the quality of the research—or even whether there was any research.”
— Joel Best, Stat-Spotting, Chapter 4