@lanka-data-layer/census

Offline Sri Lankan census indicators — 2024 population, age structure, ethnicity, and religion for the country, all 25 districts, and all 339 DS divisions (365 p-coded units in total), plus a 2012-vs-2024 comparison for the 25 districts. The dataset ships inside the package: no network calls, no filesystem reads, nothing to configure. Works in Node 18+, browsers, and edge runtimes (Workers, Deno, Bun) alike — it's just data and pure functions.

Install

npm install @lanka-data-layer/census

Quick start

import { CENSUS_YEAR, coveredPcodes, population, ethnicity, religion, demographics } from "@lanka-data-layer/census";

CENSUS_YEAR; // 2024

coveredPcodes().length; // 365 — country ("LK") + 25 districts + 339 DS divisions

population("LK11");
// { total: 2375415, male: 1154799, female: 1220616,
//   ages: { "0-14": 392721, "15-59": 1525340, "60-64": 136268, "65+": 321086 } }

ethnicity("LK11");
// [{ key: "sinhala", count: 1807945, share: 0.7611 }, { key: "moor", count: 285346, share: 0.1201 }, ...]

religion("LK11");
// [{ key: "buddhist", count: 1682524, share: 0.7083 }, ...]

demographics("LK11");
// {
//   pcode: "LK11", censusYear: 2024,
//   population: { total: 2375415, male: 1154799, female: 1220616, sexRatio: 94.6, femaleShare: 0.5139 },
//   age: {
//     buckets: [{ bucket: "0-14", count: 392721, share: 0.1653 }, ...],
//     dependencyRatio: 43, workingAgeShare: 0.6995, childShare: 0.1653, elderlyShare: 0.1352,
//   },
//   ethnicity: [...], religion: [...],
//   change2012: {
//     ethnicity: [{ key: "sinhala", share2012: 0.7454, share2024: 0.7611, delta: 0.0157 }, ...],
//     religion: [...],
//   },
// }

Every function returns null for a p-code this dataset doesn't cover — there's no need to wrap calls in try/catch. population, ethnicity, and religion cover all 365 p-codes; GN divisions (level 4) are outside 2024 census coverage and always resolve to null.

Data model

• population(pcode) — raw 2024 counts: { total, male, female, ages }, where ages is keyed by the census's four coarse buckets ("0-14", "15-59", "60-64", "65+" — the published tables carry no finer breakdown and no sex-by-age cross-tabulation).
• ethnicity(pcode) / religion(pcode) — { key, count, share }[], descending by count. share is a fraction of the group's own total (all ethnicity counts, or all religion counts), four decimal places.
• demographics(pcode) — the full derived profile, matching the indicators served by the hosted API's /v1/demographics endpoint: population with sexRatio (males per 100 females) and femaleShare; age with per-bucket shares plus dependencyRatio ((0-14 + 65+) / (15-59 + 60-64) * 100), workingAgeShare, childShare, and elderlyShare; ethnicity and religion breakdowns; and change2012, a 2012-vs-2024 comparison restricted to keys present in both census years, null for any p-code outside the 25 districts the 2012 census covered.
• coveredPcodes() — every p-code with 2024 census data, for iterating the full dataset or checking coverage up front.

All types are exported — Population, StatEntry, AgeBucket, AgeBucketShare, ChangeEntry, Demographics, SourceAttribution.

Data provenance

| Source | License | |---|---| | Department of Census and Statistics, Sri Lanka | Not stated (government statistical publication) |

The same attribution is exported at runtime as SOURCES: SourceAttribution[]. The Department of Census and Statistics publishes the 2024 Census of Population and Housing tables without explicit license terms on the source pages; this package reproduces them as a public government statistical publication, with full attribution.

Versioning and freshness

DATA_VERSION (format YYYYMMDD.N) is exported alongside the data and tracks the build that produced it — compare it against a previously cached value to detect a stale copy. This package is a point-in-time snapshot generated by the Lanka Data Layer monorepo's foundry ETL pipeline; a new release is cut whenever the underlying census data changes. If you need indicators this snapshot doesn't cover, check the hosted API or open an issue.

Part of Lanka Data Layer

This package is one piece of Lanka Data Layer, an open geo-data platform for Sri Lanka — reverse geocoding, universal search, postal codes, population, and election results for every GN division, DS division, district, and province on the island. If you'd rather query this data over HTTP instead of bundling it, the same indicators are served at lanka-data-layer.prabhavalabs.com (GET /v1/demographics/:pcode). See also @lanka-data-layer/electoral for election results.

License

MIT — see LICENSE. Census data remains under the source's own terms (see Data provenance above); please preserve attribution to the Department of Census and Statistics, Sri Lanka in anything you build with it.