condition mean min max ZT0-3 10.421921 10.421921 10.421921 ZT4-7 11.680589 11.680589 11.680589 ZT8-11 11.5617095 11.5617095 11.5617095 ZT12-15 13.406943 13.406943 13.406943 ZT16-19 12.4847695 12.4847695 12.4847695 ZT20-23 12.2953505 12.2953505 12.2953505