condition mean min max ZT0-3 8.032955 8.032955 8.032955 ZT4-7 9.589215 9.589215 9.589215 ZT8-11 6.338514999999999 6.338514999999999 6.338514999999999 ZT12-15 5.262715 5.262715 5.262715 ZT16-19 5.625825000000001 5.625825000000001 5.625825000000001 ZT20-23 6.009895 6.009895 6.009895