condition mean min max ZT0-3 16.395347 16.395347 16.395347 ZT4-7 12.979138 12.979138 12.979138 ZT8-11 12.8026465 12.8026465 12.8026465 ZT12-15 12.2594455 12.2594455 12.2594455 ZT16-19 12.3337895 12.3337895 12.3337895 ZT20-23 13.6036125 13.6036125 13.6036125