condition mean min max ZT0-3 7.182595 6.65308 7.930785 ZT4-7 5.625954999999999 5.625954999999999 5.625954999999999 ZT8-11 6.92699 6.92699 6.92699 ZT12-15 12.344025 11.286850000000001 13.4012 ZT16-19 10.19735 10.19735 10.19735 ZT20-23 9.423465 9.423465 9.423465