condition mean min max ZT0-3 5.455195 5.455195 5.455195 ZT4-7 4.283335 4.283335 4.283335 ZT8-11 4.426025 4.426025 4.426025 ZT12-15 4.04581 4.04581 4.04581 ZT16-19 5.092295 5.092295 5.092295 ZT20-23 5.193705 5.193705 5.193705