condition mean min max ZT0-3 0.805237 0.805237 0.805237 ZT4-7 0.8868135 0.8868135 0.8868135 ZT8-11 0.636552 0.636552 0.636552 ZT12-15 1.1263855 1.1263855 1.1263855 ZT16-19 1.2184945 1.2184945 1.2184945 ZT20-23 0.77494 0.77494 0.77494