condition mean min max ZT0-3 6.685078333333333 6.1627600000000005 7.06236 ZT4-7 5.236565 5.236565 5.236565 ZT8-11 5.525024999999999 5.525024999999999 5.525024999999999 ZT12-15 7.1467125 6.997795 7.29563 ZT16-19 5.975545 5.975545 5.975545 ZT20-23 9.370004999999999 9.370004999999999 9.370004999999999