condition mean min max ZT0-3 9.292895 9.292895 9.292895 ZT4-7 7.218505 7.218505 7.218505 ZT8-11 6.63378 6.63378 6.63378 ZT12-15 6.543704999999999 6.543704999999999 6.543704999999999 ZT16-19 10.74542 10.74542 10.74542 ZT20-23 12.06175 12.06175 12.06175