condition mean min max ZT0-3 8.85061 8.85061 8.85061 ZT4-7 8.98767 8.98767 8.98767 ZT8-11 6.135915000000001 6.135915000000001 6.135915000000001 ZT12-15 6.65423 6.65423 6.65423 ZT16-19 7.42701 7.42701 7.42701 ZT20-23 8.8499 8.8499 8.8499