condition mean min max ZT0-3 20.186574999999998 17.3456 23.027549999999998 ZT4-7 12.75655 12.75655 12.75655 ZT8-11 11.7701 11.7701 11.7701 ZT12-15 0 0 0 ZT16-19 19.461 19.461 19.461 ZT20-23 17.9964 17.9964 17.9964