condition mean min max ZT0-3 12.685265 12.685265 12.685265 ZT4-7 14.998313 14.998313 14.998313 ZT8-11 12.050154500000001 12.050154500000001 12.050154500000001 ZT12-15 12.698139999999999 12.698139999999999 12.698139999999999 ZT16-19 14.312317499999999 14.312317499999999 14.312317499999999 ZT20-23 19.774982 19.774982 19.774982