condition mean min max ZT0-3 21.933647 21.933647 21.933647 ZT4-7 20.6650655 20.6650655 20.6650655 ZT8-11 13.695187 13.695187 13.695187 ZT12-15 12.628917 12.628917 12.628917 ZT16-19 8.778556 8.778556 8.778556 ZT20-23 9.433498 9.433498 9.433498