condition mean min max ZT0-3 663.551317 663.551317 663.551317 ZT4-7 511.65009150000003 511.65009150000003 511.65009150000003 ZT8-11 635.9362945 635.9362945 635.9362945 ZT12-15 660.4680725000001 660.4680725000001 660.4680725000001 ZT16-19 710.5406820000001 710.5406820000001 710.5406820000001 ZT20-23 704.810643 704.810643 704.810643