condition mean min max ZT0-3 6.445105 6.445105 6.445105 ZT4-7 4.609225 4.609225 4.609225 ZT8-11 4.884175 4.884175 4.884175 ZT12-15 5.145795 5.145795 5.145795 ZT16-19 7.088075 7.088075 7.088075 ZT20-23 6.9085149999999995 6.9085149999999995 6.9085149999999995