condition mean min max ZT0-3 6.456916666666667 5.4577100000000005 7.782885 ZT4-7 5.061645 5.061645 5.061645 ZT8-11 5.8977 5.8977 5.8977 ZT12-15 7.5423725 7.295405 7.78934 ZT16-19 5.4076249999999995 5.4076249999999995 5.4076249999999995 ZT20-23 4.09074 4.09074 4.09074