condition mean min max ZT0-3 551.5191666666666 484.34299999999996 613.168 ZT4-7 345.26099999999997 345.26099999999997 345.26099999999997 ZT8-11 294.97450000000003 294.97450000000003 294.97450000000003 ZT12-15 409.19325000000003 390.5085 427.87800000000004 ZT16-19 431.975 431.975 431.975 ZT20-23 476.808 476.808 476.808