condition mean min max ZT0-3 6.775463333333334 5.751775 7.6568950000000005 ZT4-7 6.147195 6.147195 6.147195 ZT8-11 5.669245 5.669245 5.669245 ZT12-15 7.736845 6.867675 8.606015 ZT16-19 5.726025 5.726025 5.726025 ZT20-23 6.790305 6.790305 6.790305