condition mean min max ZT0-3 9.458319 9.458319 9.458319 ZT4-7 10.9604645 10.9604645 10.9604645 ZT8-11 13.2410925 13.2410925 13.2410925 ZT12-15 11.196666 11.196666 11.196666 ZT16-19 13.8525995 13.8525995 13.8525995 ZT20-23 9.365836 9.365836 9.365836