condition mean min max ZT0-3 1.428655 1.428655 1.428655 ZT4-7 1.467524 1.467524 1.467524 ZT8-11 0.9391625 0.9391625 0.9391625 ZT12-15 0.8719790000000001 0.8719790000000001 0.8719790000000001 ZT16-19 0.7269585000000001 0.7269585000000001 0.7269585000000001 ZT20-23 1.111305 1.111305 1.111305