condition mean min max ZT0-3 505.339733 505.339733 505.339733 ZT4-7 551.237553 551.237553 551.237553 ZT8-11 328.94122400000003 328.94122400000003 328.94122400000003 ZT12-15 208.1492155 208.1492155 208.1492155 ZT16-19 132.749813 132.749813 132.749813 ZT20-23 140.0163415 140.0163415 140.0163415