condition mean min max ZT0-3 3.19189535675 2.164039743 4.2197509705 ZT4-7 10.124282804749999 8.1515942445 12.096971365 ZT8-11 11.45030462275 10.337326770499999 12.563282475 ZT12-15 12.51165353475 9.7635170545 15.259790015 ZT16-19 9.06801615325 8.7209907045 9.415041602 ZT20-23 7.694156183 7.497981296999999 7.890331069