condition mean min max ZT0-3 1.0186961666666665 0.878286 1.2244 ZT4-7 0.7347494999999999 0.7347494999999999 0.7347494999999999 ZT8-11 0.8121525 0.8121525 0.8121525 ZT12-15 1.69061 1.607195 1.774025 ZT16-19 1.577 1.577 1.577 ZT20-23 1.440775 1.440775 1.440775