condition mean min max ZT0-3 6.65453 6.33661 6.97245 ZT4-7 8.957745 8.957745 8.957745 ZT8-11 10.034995 10.034995 10.034995 ZT12-15 0 0 0 ZT16-19 9.705385 9.705385 9.705385 ZT20-23 8.097895 8.097895 8.097895