condition mean min max ZT0-3 3.00478417475 2.5812510090000003 3.4283173405 ZT4-7 3.0057989467499997 2.995878167 3.0157197264999995 ZT8-11 9.207092925 6.3351465854999995 12.0790392645 ZT12-15 17.563801142499997 16.919122854999998 18.20847943 ZT16-19 14.736912095000001 14.621195495 14.852628695 ZT20-23 12.0917952575 11.6727937 12.510796814999999