condition mean min max ZT0-3 9.4778175 9.428270000000001 9.527365 ZT4-7 11.68725 11.68725 11.68725 ZT8-11 12.50265 12.50265 12.50265 ZT12-15 0 0 0 ZT16-19 11.012825 11.012825 11.012825 ZT20-23 10.55185 10.55185 10.55185