condition mean min max ZT0-3 70.035374 70.035374 70.035374 ZT4-7 64.351234 64.351234 64.351234 ZT8-11 70.9557495 70.9557495 70.9557495 ZT12-15 68.15592849999999 68.15592849999999 68.15592849999999 ZT16-19 52.4966405 52.4966405 52.4966405 ZT20-23 39.898448 39.898448 39.898448