condition mean min max ZT0-3 20.389519 20.389519 20.389519 ZT4-7 18.347109 18.347109 18.347109 ZT8-11 23.441122 23.441122 23.441122 ZT12-15 16.355065500000002 16.355065500000002 16.355065500000002 ZT16-19 35.8685305 35.8685305 35.8685305 ZT20-23 41.143663 41.143663 41.143663