condition mean min max ZT0-3 11.074471 11.074471 11.074471 ZT4-7 11.2577085 11.2577085 11.2577085 ZT8-11 11.271223500000001 11.271223500000001 11.271223500000001 ZT12-15 11.6015385 11.6015385 11.6015385 ZT16-19 11.413715499999999 11.413715499999999 11.413715499999999 ZT20-23 12.554342 12.554342 12.554342