condition mean min max ZT0-3 2.83913 2.83913 2.83913 ZT4-7 1.2972000000000001 1.2972000000000001 1.2972000000000001 ZT8-11 1.326405 1.326405 1.326405 ZT12-15 2.6140350000000003 2.6140350000000003 2.6140350000000003 ZT16-19 5.06354 5.06354 5.06354 ZT20-23 3.37641 3.37641 3.37641