Original sentence: Federer is the first male player to win 20 or more Grand Slam matches per year for six years in a row (2004-09).He was 22–1 in 2004, 24–2 in 2005, 27–1 in 2006, 26–1 in 2007, 24–3 in 2008, and 20–1 in 2009
Edited sentence: Federer is the first male player to win 20 or more Grand Slam matches per year for six years in a row, (2004-09) since Ivan  Lendl won 20 Grand Slam matches for 7 consecutive years (1983-1989)