condition mean min max ZT0-3 293.064677 293.064677 293.064677 ZT4-7 111.8430945 111.8430945 111.8430945 ZT8-11 46.347241 46.347241 46.347241 ZT12-15 40.689167999999995 40.689167999999995 40.689167999999995 ZT16-19 32.254298 32.254298 32.254298 ZT20-23 40.13472 40.13472 40.13472