In 1977, the dressage scoring was changed, with each movement marked out of ten rather than out of six. This increased the maximum number of dressage marks from 144 to 240. This number later increased to 250 marks in 1998, after additional movements were added. To keep the correct weight, a formula is used to convert good marks in dressage to penalty points. First, the marks of the judges (if there is more than one) are averaged. Then the raw mark is subtracted from the maximum points possible. This number is then multiplied by 0.6 to calculate the final penalty score.