condition mean min max ZT0-3 10.107736 10.107736 10.107736 ZT4-7 11.1027135 11.1027135 11.1027135 ZT8-11 9.115426 9.115426 9.115426 ZT12-15 8.718719499999999 8.718719499999999 8.718719499999999 ZT16-19 10.026423999999999 10.026423999999999 10.026423999999999 ZT20-23 9.2983395 9.2983395 9.2983395