condition mean min max ZT0-3 25.519033333333333 12.083 36.8461 ZT4-7 15.33745 15.33745 15.33745 ZT8-11 21.922849999999997 21.922849999999997 21.922849999999997 ZT12-15 30.138325000000002 29.77355 30.5031 ZT16-19 28.293300000000002 28.293300000000002 28.293300000000002 ZT20-23 38.46145 38.46145 38.46145