condition mean min max ZT0-3 5.76421 5.22939 6.40935 ZT4-7 4.183145 4.183145 4.183145 ZT8-11 4.34023 4.34023 4.34023 ZT12-15 7.412014999999999 7.254194999999999 7.569834999999999 ZT16-19 7.033189999999999 7.033189999999999 7.033189999999999 ZT20-23 6.20867 6.20867 6.20867