condition mean min max ZT0-3 1.4441991666666667 0.2223845 3.0772950000000003 ZT4-7 0.7837529999999999 0.7837529999999999 0.7837529999999999 ZT8-11 0.815923 0.815923 0.815923 ZT12-15 0.52979775 0.2261045 0.833491 ZT16-19 3.90841 3.90841 3.90841 ZT20-23 9.07102 9.07102 9.07102