condition mean min max ZT0-3 9.660991 9.660991 9.660991 ZT4-7 9.742274 9.742274 9.742274 ZT8-11 10.7298705 10.7298705 10.7298705 ZT12-15 10.171064999999999 10.171064999999999 10.171064999999999 ZT16-19 9.704228 9.704228 9.704228 ZT20-23 9.4036985 9.4036985 9.4036985