condition mean min max ZT0-3 9.477095 8.936914999999999 10.017275000000001 ZT4-7 6.920285 6.920285 6.920285 ZT8-11 8.3429 8.3429 8.3429 ZT12-15 0 0 0 ZT16-19 11.013449999999999 11.013449999999999 11.013449999999999 ZT20-23 9.974685000000001 9.974685000000001 9.974685000000001