condition mean min max ZT0-3 1968.398904 1968.398904 1968.398904 ZT4-7 2146.0770654999997 2146.0770654999997 2146.0770654999997 ZT8-11 1953.891909 1953.891909 1953.891909 ZT12-15 1940.1281060000001 1940.1281060000001 1940.1281060000001 ZT16-19 1492.7165 1492.7165 1492.7165 ZT20-23 1204.3482414999999 1204.3482414999999 1204.3482414999999