condition mean min max ZT0-3 185.149341 185.149341 185.149341 ZT4-7 240.496639 240.496639 240.496639 ZT8-11 248.59862149999998 248.59862149999998 248.59862149999998 ZT12-15 217.664494 217.664494 217.664494 ZT16-19 338.077658 338.077658 338.077658 ZT20-23 315.9278695 315.9278695 315.9278695