Annual assessment notices will be mailed out Friday to 230,000 Cobb property owners notifying them of their 2011 property values.

The notices, required for all properties regardless if the value has changed, will include a tax estimate for all applicable taxing authorities, but won’t include city homestead exemptions or Marietta’s school tax exemption. About 90,000 of the notices will show a drop in value due to the housing market conditions and state law requirements.

The county’s tax digest, will be finalized by July 1, and millage rates are set later that month. Tax bills are mailed out in August.

Cobb’s tax digest is expected to decline about 7 percent from last year to $27 billion, according to the county’s chief appraiser.