condition mean min max ZT0-3 12.543483 12.543483 12.543483 ZT4-7 11.888311999999999 11.888311999999999 11.888311999999999 ZT8-11 11.1231205 11.1231205 11.1231205 ZT12-15 10.253614500000001 10.253614500000001 10.253614500000001 ZT16-19 10.2383515 10.2383515 10.2383515 ZT20-23 11.332578999999999 11.332578999999999 11.332578999999999