condition mean min max ZT0-3 6.521871666666667 5.26571 8.038654999999999 ZT4-7 6.430265 6.430265 6.430265 ZT8-11 33.4072 33.4072 33.4072 ZT12-15 20.646974999999998 17.103749999999998 24.190199999999997 ZT16-19 13.2483 13.2483 13.2483 ZT20-23 9.128275 9.128275 9.128275