condition mean min max ZT0-3 4.3471400000000004 3.898365 4.735950000000001 ZT4-7 3.03223 3.03223 3.03223 ZT8-11 4.0953800000000005 4.0953800000000005 4.0953800000000005 ZT12-15 5.0275275 4.75884 5.296215 ZT16-19 5.040005 5.040005 5.040005 ZT20-23 6.64051 6.64051 6.64051