condition mean min max ZT0-3 21.549785 21.549785 21.549785 ZT4-7 20.735343 20.735343 20.735343 ZT8-11 20.8738615 20.8738615 20.8738615 ZT12-15 16.7998085 16.7998085 16.7998085 ZT16-19 22.3424275 22.3424275 22.3424275 ZT20-23 26.4731435 26.4731435 26.4731435