Anxiety Disorder Statistics. Anxiety Disorders affect 18.1 percent of adults in the United States (approximately 40 million adults between the ages of 18 to 54).
Perfect square. Perfect square is an element of algebraic structure which is equal to the square of another element. Square number, a perfect square integer.
A perfect season is a sports season including any requisite playoff portion, in which a team remains undefeated and untied. The feat is extremely rare at the professional level of any team sport, and has occurred more commonly at the collegiate level in the United States.