Data are approximate to speed up querying time, but should in most cases be accurate to the hundredths place. This statistic measures the average percentage of a race a driver led and is the best measure for dominance (because very often the driver who wins the race was not the driver who dominated), and laps led is biased towards races that have larger numbers of laps, while this statistic equalizes all races. 25 or more starts are needed to appear on the list for F1, Champ Car, IndyCar, MotoGP, NASCAR Xfinity, or NASCAR Trucks, while 50 or more starts are needed for NASCAR series. Data for NASCAR Xfinity Series is only available from 1995 to present.