condition mean min max ZT0-3 18.990099999999998 18.990099999999998 18.990099999999998 ZT4-7 16.11085 16.11085 16.11085 ZT8-11 19.021900000000002 19.021900000000002 19.021900000000002 ZT12-15 14.82 14.82 14.82 ZT16-19 16.6541 16.6541 16.6541 ZT20-23 14.220749999999999 14.220749999999999 14.220749999999999