condition mean min max ZT0-3 7.47085 4.15359 9.82065 ZT4-7 5.36883 5.36883 5.36883 ZT8-11 5.236815 5.236815 5.236815 ZT12-15 6.3154225 6.309365 6.32148 ZT16-19 7.413835000000001 7.413835000000001 7.413835000000001 ZT20-23 9.615029999999999 9.615029999999999 9.615029999999999