condition mean min max ZT0-3 8.56417 8.56417 8.56417 ZT4-7 4.47799 4.47799 4.47799 ZT8-11 3.7593050000000003 3.7593050000000003 3.7593050000000003 ZT12-15 6.827439999999999 6.827439999999999 6.827439999999999 ZT16-19 15.823699999999999 15.823699999999999 15.823699999999999 ZT20-23 14.062850000000001 14.062850000000001 14.062850000000001