condition mean min max ZT0-3 1.84090714 1.733466718 1.948347562 ZT4-7 1.4790493922499999 1.366718162 1.5913806225 ZT8-11 2.2367611207499998 1.9725876435 2.5009345979999997 ZT12-15 3.108745056 2.3995635965 3.8179265155 ZT16-19 2.1583499252500005 1.9163268825000004 2.400372968 ZT20-23 4.61451800925 3.8211225385 5.4079134799999995