condition mean min max ZT0-3 14.21355 14.21355 14.21355 ZT4-7 11.1679 11.1679 11.1679 ZT8-11 7.016965 7.016965 7.016965 ZT12-15 7.237555 7.237555 7.237555 ZT16-19 14.843250000000001 14.843250000000001 14.843250000000001 ZT20-23 15.0776 15.0776 15.0776