condition mean min max ZT0-3 15.091058 15.091058 15.091058 ZT4-7 16.61494 16.61494 16.61494 ZT8-11 15.476797000000001 15.476797000000001 15.476797000000001 ZT12-15 15.704818999999999 15.704818999999999 15.704818999999999 ZT16-19 16.01436 16.01436 16.01436 ZT20-23 14.844236 14.844236 14.844236