condition mean min max ZT0-3 30.10224 30.10224 30.10224 ZT4-7 21.003387 21.003387 21.003387 ZT8-11 17.7433775 17.7433775 17.7433775 ZT12-15 25.087550999999998 25.087550999999998 25.087550999999998 ZT16-19 17.9652735 17.9652735 17.9652735 ZT20-23 29.9278905 29.9278905 29.9278905