condition mean min max ZT0-3 9.422783 9.422783 9.422783 ZT4-7 10.7074945 10.7074945 10.7074945 ZT8-11 9.740078 9.740078 9.740078 ZT12-15 11.293544 11.293544 11.293544 ZT16-19 10.703896499999999 10.703896499999999 10.703896499999999 ZT20-23 11.3934605 11.3934605 11.3934605