condition mean min max ZT0-3 6.886525 6.886525 6.886525 ZT4-7 4.517135 4.517135 4.517135 ZT8-11 7.172610000000001 7.172610000000001 7.172610000000001 ZT12-15 5.059340000000001 5.059340000000001 5.059340000000001 ZT16-19 9.098745000000001 9.098745000000001 9.098745000000001 ZT20-23 8.187100000000001 8.187100000000001 8.187100000000001