condition mean min max ZT0-3 22.934147 22.934147 22.934147 ZT4-7 19.044854 19.044854 19.044854 ZT8-11 25.415374 25.415374 25.415374 ZT12-15 21.80628 21.80628 21.80628 ZT16-19 39.915435 39.915435 39.915435 ZT20-23 31.0195955 31.0195955 31.0195955