condition mean min max ZT0-3 12.8015086325 11.231691025 14.37132624 ZT4-7 11.45579649775 9.879066535500002 13.03252646 ZT8-11 14.755075815 12.852217725 16.657933905 ZT12-15 16.6464604975 15.07151086 18.221410135 ZT16-19 12.435223712500001 11.70463157 13.165815855 ZT20-23 15.383053199999999 15.26249459 15.503611809999999