He's been in their lives for over 10 years. But it goes on, and it will evolve.â. Indeed, Grey's has persevered after the departures of several regular cast members, including Isaiah Washington, Sandra Oh, Katherine Heigl, T.R. Knight, Kate Walsh, Eric Dane, Chyler Leigh, and Kim Raver.
1 Some state that the average human attention span is approximately 5 minutes; others state that most healthy teenagers and adults are unable to sustain attention on one thing for more than about 20 minutes at a time, although they can choose repeatedly to re-focus on the same thing.
1 Less than 5% of adults participate in 30 minutes of physical activity each day; only one in three adults receive the recommended amount of physical activity each week. 2  Only 35 â 44% of adults 75 years or older are physically active, and 28-34% of adults ages 65-74 are physically active. The least likely were Delaware (46.5%), West Virginia (47.1%) and Alabama (47.5%). 2  The national average for regular exercise is 51.6%. 3  Children now spend more than seven and a half hours a day in front of a screen (e.g., TV, videogames, computer).