condition mean min max ZT0-3 2.7442349999999998 2.7442349999999998 2.7442349999999998 ZT4-7 1.751115 1.751115 1.751115 ZT8-11 2.733455 2.733455 2.733455 ZT12-15 3.815225 3.815225 3.815225 ZT16-19 4.7406500000000005 4.7406500000000005 4.7406500000000005 ZT20-23 2.31006 2.31006 2.31006