condition mean min max ZT0-3 7.485405 6.828465 8.142345 ZT4-7 11.07537 11.07537 11.07537 ZT8-11 14.411950000000001 14.411950000000001 14.411950000000001 ZT12-15 0 0 0 ZT16-19 16.3782 16.3782 16.3782 ZT20-23 12.4235 12.4235 12.4235