condition mean min max ZT0-3 12.888331 12.888331 12.888331 ZT4-7 14.283858 14.283858 14.283858 ZT8-11 11.740354 11.740354 11.740354 ZT12-15 13.664973 13.664973 13.664973 ZT16-19 11.532135499999999 11.532135499999999 11.532135499999999 ZT20-23 13.155696 13.155696 13.155696