condition mean min max ZT0-3 0.998921 0.915102 1.08274 ZT4-7 2.22399 2.22399 2.22399 ZT8-11 0.21493915 0.21493915 0.21493915 ZT12-15 0 0 0 ZT16-19 0.427737 0.427737 0.427737 ZT20-23 1.196258 1.196258 1.196258