condition mean min max ZT0-3 2.5098075 2.430315 2.5892999999999997 ZT4-7 3.442215 3.442215 3.442215 ZT8-11 4.53716 4.53716 4.53716 ZT12-15 0 0 0 ZT16-19 6.9858899999999995 6.9858899999999995 6.9858899999999995 ZT20-23 3.752965 3.752965 3.752965