| Fictional population | Lower-priced group | Higher-priced group | Mean annual premium |
|---|---|---|---|
| Population A | 80 dogs at $500 | 20 dogs at $1,000 | $600 |
| Population B | 50 dogs at $500 | 50 dogs at $1,000 | $750 |
These invented populations demonstrate arithmetic, not NAPHIA’s underlying records. In the first, total premium is $60,000 across 100 dogs. In the second it is $75,000 across 100 dogs. The mean rises by $150 even though the two group prices do not change. Only the mix changes.
Real market movements can have more than one cause, including changes in rates, pet characteristics and benefits. This example does not estimate their contributions. It shows why an aggregate change cannot, by itself, tell you how much the same dog’s renewal increased.
Do not use this exercise to dismiss a real premium increase. Your actual renewal notice is direct evidence about your policy. The national average answers a different question and cannot explain away a change you were actually offered.