condition mean min max ZT0-3 3.93713 3.93713 3.93713 ZT4-7 2.676225 2.676225 2.676225 ZT8-11 3.001125 3.001125 3.001125 ZT12-15 4.441605 4.441605 4.441605 ZT16-19 5.020325 5.020325 5.020325 ZT20-23 3.9773199999999997 3.9773199999999997 3.9773199999999997