condition mean min max ZT0-3 17.475025000000002 16.62675 18.3233 ZT4-7 9.635480000000001 9.635480000000001 9.635480000000001 ZT8-11 7.395435 7.395435 7.395435 ZT12-15 0 0 0 ZT16-19 11.54925 11.54925 11.54925 ZT20-23 12.1344 12.1344 12.1344