condition mean min max ZT0-3 6.085909688 2.074521656 10.09729772 ZT4-7 2.554721346 1.8249838145 3.2844588775 ZT8-11 4.1654297725 3.4756072579999997 4.855252287 ZT12-15 6.66754264175 4.7609785764999994 8.574106707 ZT16-19 3.2864907535000003 3.0353061485 3.5376753585000005 ZT20-23 6.07067651575 4.899339284 7.2420137475