condition mean min max ZT0-3 8.5795325 7.004215 10.15485 ZT4-7 10.17717 10.17717 10.17717 ZT8-11 10.182749999999999 10.182749999999999 10.182749999999999 ZT12-15 0 0 0 ZT16-19 12.98684 12.98684 12.98684 ZT20-23 9.429835 9.429835 9.429835