condition mean min max ZT0-3 10.112581 10.112581 10.112581 ZT4-7 11.5404745 11.5404745 11.5404745 ZT8-11 8.380343499999999 8.380343499999999 8.380343499999999 ZT12-15 10.289062999999999 10.289062999999999 10.289062999999999 ZT16-19 8.678213 8.678213 8.678213 ZT20-23 8.672532 8.672532 8.672532