condition mean min max ZT0-3 5.013096666666667 4.0409749999999995 6.7334499999999995 ZT4-7 11.19485 11.19485 11.19485 ZT8-11 24.649099999999997 24.649099999999997 24.649099999999997 ZT12-15 16.678874999999998 13.9847 19.37305 ZT16-19 9.925145 9.925145 9.925145 ZT20-23 7.241574999999999 7.241574999999999 7.241574999999999