DDL Historical Urban Population

Dataset: population-historical
Package scope: Released parent agglomerations and their ADM1 and ADM2 splits, every published year
Dataset version: v0.3.0

Contents
- ddl-population-historical.parquet: the full table
- ddl-population-historical.csv: the same rows as text
- This README

Schema
- id: Parent or child city identifier.
- version: Boundary version.
- boundary_level: `PARENT`, `ADM1` or `ADM2`.
- year: Year of the population estimate.
- pop_sum: Population total for the given year.
- pixel_count: Number of raster pixels contributing to `pop_sum` at five-year source epochs.

Notes
- 681,666 rows covering 1975-2025.
- ids include UA-ADM split rows, not only parent agglomerations.
- Published split polygons may not cover the whole parent; their totals need not sum to the parent total.
- Filter boundary_level before aggregating; summing pop_sum across every row double counts parents against their own splits.

License
- Released under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Disclaimer
By accepting data provided by the Development Data Lab (DDL), you agree to the following conditions of release and acknowledge the following disclaimers: Neither DDL nor the contributors of data to DDL shall be held liable for any improper or incorrect use or application of the data provided, and assume no responsibility for the use or application of the data or information derived from interpretation of the data. In no event shall DDL or its collaborators be liable for any direct, indirect, or incidental damages arising from the use or application of these data. This disclaimer of liability applies to any damages or injury, including but not limited to those caused by any failure of performance, error, omission, defect, delay in operation or transmission, computer virus, alteration, use, application, analysis, or interpretation of data. No warranty, expressed or implied, is made regarding the accuracy, adequacy, completeness, reliability, or usefulness of any data provided. These data are provided on an "as is" basis. All warranties of any kind, express or implied, including but not limited to fitness for a particular use, freedom from computer viruses, and non-infringement of proprietary rights, are disclaimed. Data are added and changed periodically, and data may become out-of-date quickly. It is recommended that the user not let a significant period of time elapse between obtaining and using the data.
