Auto Brand Quality by the Average of Overall Reliability Ratingsだよ。
To compute car-brand quality ratings and compute a quality rank using Consumer Reports' overall reliability ratings, a number is first associated with each of CR's overall ratings. A +1.0 is ascribed to a rating of Much Better Than Average, a +0.5 to a rating of Better Than Average, a 0 to a rating of Average, a -0.5 to a rating of Worse Than Average, and a -1.0 to a rating of Much Worse Than Average. Then an average is taken over all of the brand's model years and models offering an overall reliability rating. Lastly, the automobile brands with at least 5 overall reliability ratings are ordered from best to worst for each of the years 1975, 1980, 1985, 1990, 2000, 2005, and 2010. The best brand in a given year has a quality rank of 1. だよ。