Local Population Estimates 

Data sets used to construct estimates:

• ONS mid-year local authority estimates (by sex and 5 year age bands)

• Annual population downloads from the Exeter System containing patient GP registrations. 

• Mid-1998 ward level estimates by DETR (3 age bands: 0-15, 16-59, 60+)

Method -Base Year

Step 1: Aggregate 1998 Exeter data into required age/sex/ward bands. 
Step 2: Calculate Exeter to DETR adjustment factors

e.g. Knowle

Step 3: Adjust Exeter population derived in step A by adjustment factor derived in step B. Exeter populations now 'controlled' to DETR.
Step 4: Aggregate adjusted Exeter population wards up to local authority
Step 5: Calculate modified Exeter to ONS mid-year estimate adjustment factors

e.g. BANES

Step 6: Apply adjustment factors derived in step C to individual wards of modified Exeter populations from step C. Exeter populations now modified by DETR estimates and 'controlled' to ONS estimates. 

Method - Other Years

Step 1: Aggregate 1999 Exeter data into required age/sex/ward bands.
Step 2:  Calculate proportionate change between 1998 and 1999 Exeter populations

e.g. Knowle

Step 3:  Apply the proportions from step (b) to the mid-1998 population estimate to produce unadjusted 1999 estimate
Step 4: Aggregate unadjusted 1999 estimate wards up to local authority areas
Step 5: Control to ONS estimates using same methods employed in base year calculations 
Step 6:  Apply adjustment factors derived in step (e) to individual wards of unadjusted 1999 estimate from step (c).