condition mean min max ZT0-3 16.86466666666667 10.66205 21.15085 ZT4-7 8.192245 8.192245 8.192245 ZT8-11 5.82208 5.82208 5.82208 ZT12-15 8.5728775 7.991185 9.15457 ZT16-19 10.19305 10.19305 10.19305 ZT20-23 19.15355 19.15355 19.15355