condition mean min max ZT0-3 8.971831666666667 8.723704999999999 9.390235 ZT4-7 6.249745 6.249745 6.249745 ZT8-11 6.354645 6.354645 6.354645 ZT12-15 12.370574999999999 11.9123 12.82885 ZT16-19 14.1651 14.1651 14.1651 ZT20-23 13.6182 13.6182 13.6182