A board of six people rates each horse according to its past-performances in previous races. This is called official rating. The official rating can be affected by factors such as age as horses between the age 3-5 will be adjusted on a scale known as Weight for Age (WFA) by which a five year old horse will get a higher rating than a three year old horse. When a horse has run a set number of races, it obtains an official rating, which allows it to enter a handicap race. All official ratings are stored by the horse racing administrations. Ratings are adjusted weekly according to the number of races the horse has run and its respective results.