As of 2005, Barbara Blackburn was the fastest English language typist in the world, according to The Guinness Book of World Records. Using the Dvorak Simplified Keyboard, she has maintained 150 words per minute (wpm) for 50 minutes, and 170 wpm for shorter periods. She has been clocked at a peak speed of 212 wpm. Blackburn, who failed her typing class in high school, first encountered the Dvorak keyboard in 1938, quickly learned to achieve very high speeds, and occasionally toured giving speed-typing demonstrations during her secretarial career. She appeared on The David Letterman Show and was deeply offended by Letterman’s comedic treatment of her skill. Blackburn died in April 2008.