condition mean min max ZT0-3 21.788888890000003 21.788888890000003 21.788888890000003 ZT4-7 14.440000001000001 14.440000001000001 14.440000001000001 ZT8-11 8.185 8.185 8.185 ZT12-15 6.004444444333333 6.004444444333333 6.004444444333333 ZT16-19 6.424444444333333 6.424444444333333 6.424444444333333 ZT20-23 13.145555554333333 13.145555554333333 13.145555554333333