condition mean min max ZT0-3 15.776499999999999 15.2592 16.293799999999997 ZT4-7 8.051224999999999 8.051224999999999 8.051224999999999 ZT8-11 6.454045 6.454045 6.454045 ZT12-15 0 0 0 ZT16-19 12.18835 12.18835 12.18835 ZT20-23 12.2481 12.2481 12.2481