condition mean min max ZT0-3 1.5769144555 1.4275977180000001 1.726231193 ZT4-7 3.5082056232500003 2.4029624465 4.6134488000000005 ZT8-11 5.17385489125 4.4400472165 5.907662566 ZT12-15 6.5919169882499995 5.655047165499999 7.528786811 ZT16-19 6.52400619575 5.716598741 7.3314136505 ZT20-23 8.820615811 8.4019032535 9.2393283685