condition mean min max ZT0-3 15.435486666666668 9.52431 21.803350000000002 ZT4-7 17.6783 17.6783 17.6783 ZT8-11 11.08905 11.08905 11.08905 ZT12-15 11.8756675 9.452935 14.2984 ZT16-19 6.680210000000001 6.680210000000001 6.680210000000001 ZT20-23 10.646640000000001 10.646640000000001 10.646640000000001