condition mean min max ZT0-3 24.412501 24.412501 24.412501 ZT4-7 17.0969005 17.0969005 17.0969005 ZT8-11 19.7046705 19.7046705 19.7046705 ZT12-15 20.502254 20.502254 20.502254 ZT16-19 19.1388025 19.1388025 19.1388025 ZT20-23 21.755999000000003 21.755999000000003 21.755999000000003