condition mean min max ZT0-3 1982.6 1982.6 1982.6 ZT4-7 1121.7 1121.7 1121.7 ZT8-11 1209.0 1209.0 1209.0 ZT12-15 1489.45 1489.45 1489.45 ZT16-19 1727.9499999999998 1727.9499999999998 1727.9499999999998 ZT20-23 2038.4 2038.4 2038.4