condition mean min max ZT0-3 29.362000000000002 26.49045 32.23355 ZT4-7 23.6186 23.6186 23.6186 ZT8-11 15.86585 15.86585 15.86585 ZT12-15 0 0 0 ZT16-19 23.052500000000002 23.052500000000002 23.052500000000002 ZT20-23 24.1163 24.1163 24.1163