condition mean min max ZT0-3 4.559362569 3.282229801 5.836495337000001 ZT4-7 2.46233375575 2.0054024355 2.919265076 ZT8-11 1.9431020672500001 1.547274394 2.3389297405000002 ZT12-15 2.34596443375 2.2942818999999997 2.3976469675 ZT16-19 6.081487378 4.155842181 8.007132575 ZT20-23 14.354085395 14.05186659 14.656304200000001