condition mean min max ZT0-3 19.047725 17.3228 20.77265 ZT4-7 15.742049999999999 15.742049999999999 15.742049999999999 ZT8-11 21.9281 21.9281 21.9281 ZT12-15 0 0 0 ZT16-19 26.7553 26.7553 26.7553 ZT20-23 23.9691 23.9691 23.9691