condition mean min max ZT0-3 3.1338616779999997 2.934951871 3.332771485 ZT4-7 4.39975140475 3.5174908370000004 5.282011972499999 ZT8-11 5.4793141597499995 4.852595524 6.106032795499999 ZT12-15 7.9464354585 7.3400698385 8.5528010785 ZT16-19 8.915588872999999 7.065629852 10.765547894 ZT20-23 13.376002490000001 12.62196477 14.13004021