condition mean min max ZT0-3 11.017476 11.017476 11.017476 ZT4-7 12.160026 12.160026 12.160026 ZT8-11 10.521661 10.521661 10.521661 ZT12-15 10.066143 10.066143 10.066143 ZT16-19 11.918739 11.918739 11.918739 ZT20-23 10.0424205 10.0424205 10.0424205