condition mean min max ZT0-3 5.87734 5.87734 5.87734 ZT4-7 5.17099 5.17099 5.17099 ZT8-11 4.576465 4.576465 4.576465 ZT12-15 3.9993499999999997 3.9993499999999997 3.9993499999999997 ZT16-19 7.006815 7.006815 7.006815 ZT20-23 6.841795 6.841795 6.841795