condition mean min max ZT0-3 17.346331 17.346331 17.346331 ZT4-7 12.755562000000001 12.755562000000001 12.755562000000001 ZT8-11 9.4902665 9.4902665 9.4902665 ZT12-15 10.7832085 10.7832085 10.7832085 ZT16-19 10.9505755 10.9505755 10.9505755 ZT20-23 12.1504285 12.1504285 12.1504285