> For the complete documentation index, see [llms.txt](https://www.csvpath.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://www.csvpath.org/getting-started/the-flightpath-data-examples/duplicates/percent-overlapping.md).

# Percent overlapping

{% hint style="success" %}
Run this example using its test data from within [FlightPath Data](https://www.flightpathdata.com/).
{% endhint %}

```
~
   Find the % of overlapping records for three headers.
   name:
   test-data: examples/duplicates/Alzheimers_Disease_and_Healthy_Aging_Data_sample.csv
~

$[1*][
   dup_lines(#Stratification1, #Stratification2, #LocationID)
   @p = percent("match")
   @p = multiply(@p, 100)
   @p = int(@p)
   last.nocontrib() -> print("Out of $.csvpath.line_number lines with $.csvpath.count_matches matches, $.variables.p% overlap on age, race, and location")
]
```