condition mean min max ZT0-3 8.835294999999999 8.835294999999999 8.835294999999999 ZT4-7 6.62777 6.62777 6.62777 ZT8-11 7.2277000000000005 7.2277000000000005 7.2277000000000005 ZT12-15 6.002929999999999 6.002929999999999 6.002929999999999 ZT16-19 9.47157 9.47157 9.47157 ZT20-23 9.465955000000001 9.465955000000001 9.465955000000001