condition mean min max ZT0-3 1.6967138333333334 1.0776215 2.323045 ZT4-7 2.441225 2.441225 2.441225 ZT8-11 0.8238955 0.8238955 0.8238955 ZT12-15 0.6310942500000001 0.35686700000000005 0.9053215 ZT16-19 0.675323 0.675323 0.675323 ZT20-23 1.2675745 1.2675745 1.2675745