condition mean min max ZT0-3 26.66025 25.54005 27.780450000000002 ZT4-7 19.5201 19.5201 19.5201 ZT8-11 24.752200000000002 24.752200000000002 24.752200000000002 ZT12-15 0 0 0 ZT16-19 26.490099999999998 26.490099999999998 26.490099999999998 ZT20-23 30.683 30.683 30.683