condition mean min max ZT0-3 16.058753 16.058753 16.058753 ZT4-7 16.740424 16.740424 16.740424 ZT8-11 17.224335500000002 17.224335500000002 17.224335500000002 ZT12-15 16.9539775 16.9539775 16.9539775 ZT16-19 18.260855 18.260855 18.260855 ZT20-23 17.681743 17.681743 17.681743