condition mean min max ZT0-3 2.85862 2.45327 3.26397 ZT4-7 3.0078500000000004 3.0078500000000004 3.0078500000000004 ZT8-11 3.31884 3.31884 3.31884 ZT12-15 0 0 0 ZT16-19 3.14008 3.14008 3.14008 ZT20-23 4.523725000000001 4.523725000000001 4.523725000000001