condition mean min max ZT0-3 17.654816666666665 14.4497 21.5313 ZT4-7 13.7375 13.7375 13.7375 ZT8-11 11.26575 11.26575 11.26575 ZT12-15 16.7826425 12.770085 20.7952 ZT16-19 14.615649999999999 14.615649999999999 14.615649999999999 ZT20-23 19.2494 19.2494 19.2494