condition mean min max ZT0-3 46.218828 46.218828 46.218828 ZT4-7 36.347059 36.347059 36.347059 ZT8-11 40.0964455 40.0964455 40.0964455 ZT12-15 36.713668999999996 36.713668999999996 36.713668999999996 ZT16-19 31.032549000000003 31.032549000000003 31.032549000000003 ZT20-23 29.038559499999998 29.038559499999998 29.038559499999998