condition mean min max ZT0-3 9.980446666666667 6.858115 13.437850000000001 ZT4-7 4.507575 4.507575 4.507575 ZT8-11 9.368125 9.368125 9.368125 ZT12-15 17.711399999999998 16.24225 19.18055 ZT16-19 16.6097 16.6097 16.6097 ZT20-23 15.95625 15.95625 15.95625