condition mean min max ZT0-3 9.169417 9.169417 9.169417 ZT4-7 9.75374 9.75374 9.75374 ZT8-11 9.011713499999999 9.011713499999999 9.011713499999999 ZT12-15 9.806136500000001 9.806136500000001 9.806136500000001 ZT16-19 9.301726500000001 9.301726500000001 9.301726500000001 ZT20-23 9.974272 9.974272 9.974272