condition mean min max ZT0-3 11.175704 11.175704 11.175704 ZT4-7 13.4664635 13.4664635 13.4664635 ZT8-11 17.501566 17.501566 17.501566 ZT12-15 13.717000500000001 13.717000500000001 13.717000500000001 ZT16-19 10.7171305 10.7171305 10.7171305 ZT20-23 11.532164 11.532164 11.532164