condition mean min max ZT0-3 379.871748 379.871748 379.871748 ZT4-7 332.7863615 332.7863615 332.7863615 ZT8-11 271.95777050000004 271.95777050000004 271.95777050000004 ZT12-15 296.84688900000003 296.84688900000003 296.84688900000003 ZT16-19 231.47853800000001 231.47853800000001 231.47853800000001 ZT20-23 204.4062735 204.4062735 204.4062735