The divorce rate refers to the proportion of divorced couples in a given region during the year relative to the annual average population of that region, expressed per thousand. On this website, the divorce rate refers to the annual divorce rate.

The formula is:

Divorce Rate = Number of Divorces During the Year / Annual Average Population × 1000‰

The annual average population refers to the average of the population at the beginning and end of the year. In some cases, the mid-year population may also be used as a substitute.

Divorce rates can shift over time alongside broader social, legal, and demographic changes. Comparing regional trends helps show where divorce patterns have risen, declined, or diverged from the national average.

The refined divorce rate is a custom statistic derived for this website. It adjusts annual divorce registrations by the government-published count of Females Age 15+ With Spouses, giving a more marriage-population-specific view than the crude divorce rate.

The formula is:

Refined Divorce Rate = New Divorces During the Year / Females Age 15+ With Spouses × 1000‰

Because the final rate is derived by this website, it should be read as an analytical indicator rather than a directly published official rate. The underlying denominator, Females Age 15+ With Spouses, comes from government statistical data.

The government source notes that 2005 and 2015 are based on 1% population sample survey data, while other years use 1‰ population change survey samples. This means values across years are comparable as official sample-based estimates, but the sampling basis is not identical in every year.

The source also notes that weighted aggregation can create small differences between national totals and the sum of detailed subgroups. For this chart, that means tiny inconsistencies may appear when comparing national figures with regional or grouped values, especially after deriving a rate from the published counts.