condition mean min max ZT0-3 13.615643 13.615643 13.615643 ZT4-7 13.1430515 13.1430515 13.1430515 ZT8-11 16.646645 16.646645 16.646645 ZT12-15 24.438288 24.438288 24.438288 ZT16-19 17.8366845 17.8366845 17.8366845 ZT20-23 21.4153115 21.4153115 21.4153115