condition mean min max ZT0-3 1.7534 1.7534 1.7534 ZT4-7 2.554185 2.554185 2.554185 ZT8-11 1.236405 1.236405 1.236405 ZT12-15 2.74071 2.74071 2.74071 ZT16-19 2.3734349999999997 2.3734349999999997 2.3734349999999997 ZT20-23 2.21027 2.21027 2.21027