Does that sound like a significant amount? You bet. From the article (WaPo):
"Anything over 1 percent would raise a red flag, particularly for the manufacturer," said James C. Fell, who worked at the National Highway Traffic Safety Administration for 30 years, and was chief of research for traffic safety programs.
The recent recall of 2.3 million Toyotas and the unprecedented halt in sales of several popular models because of faulty accelerator pedals raises questions about why Toyota and the NHTSA had failed to bring the problem to light previously.
In another hit to Toyota's reputation, the Japanese government has recently ordered Toyota to investigate the braking system on the 2010 Prius, following which the United States said it would begin an inquiry as well. This also raises questions about the efficacy of the NHTSA, as 111 of the 171 complaints filed with the agency by 2010 Prius owners involved brake problems.