condition mean min max ZT0-3 2.509856666666667 1.36236 3.7918700000000003 ZT4-7 2.079175 2.079175 2.079175 ZT8-11 0.971581 0.971581 0.971581 ZT12-15 1.07481 1.037725 1.111895 ZT16-19 0.919292 0.919292 0.919292 ZT20-23 2.081775 2.081775 2.081775