Document web copy

README.md

@@ -9,6 +9,8 @@ size_categories:
 configs:
   - config_name: trade
     data_files: ITPD_E_R2025_usd.parquet
+  - config_name: web
+    data_files: web/ITPD_E_R2025_web.parquet
 ---
 
 # ITPD-E R2025 — compact parquet + lookup tables
@@ -25,6 +27,7 @@ Gravity Dataset. It powers the
 | File | Rows | Description |
 |---|---|---|
 | `ITPD_E_R2025_usd.parquet` | 87,537,140 | One row per exporter × importer × industry × year, 1986–2023 (150 MB, zstd) |
+| `web/ITPD_E_R2025_web.parquet` | 33,468,219 | Smaller copy for the website (81 MB) — see below |
 | `lookups/country.csv` | 257 | Country codes used in ITPD-E: ISO 3166-1 alpha-2/3/numeric, former ISO 3166-3 codes, UN M49 regions, LDC/LLDC/SIDS flags, World Bank region/income/lending (current) |
 | `lookups/country_year.csv` | 8,617 | ISO3 + year → ITPD-E/DGD dynamic code and the name used that year |
 | `lookups/country_successor.csv` | 36 | Former countries / aggregates → successor states (e.g. SVU → 15 states) |
@@ -44,6 +47,18 @@ Gravity Dataset. It powers the
 USD; values were multiplied by 1,000,000 and rounded to the nearest dollar
 (max change $0.50 per row; 99.5% of rows unchanged).
 
+## Web copy (`web/ITPD_E_R2025_web.parquet`)
+
+The [International Trade Explorer](https://mrtimo.github.io/itpde/) downloads this
+81 MB file instead of the 150 MB full table. Same 13 columns, but:
+
+- only rows with positive trade (zero-trade rows dropped: 54.1M rows flagged `u`/`r`);
+- `trade` rounded to the nearest $1,000 (values under $1,000 kept exact, so no positive flow becomes zero);
+- `flag_mirror`, `exporter_name` and `importer_name` are left empty (use `lookups/country.csv` / `country_year.csv` for names).
+
+Row counts of positive flows are identical to the full table; the largest difference in
+any exporter × importer × year total is $14,172. **Use the full table for research.**
+
 ## Joins
 
 - Country attributes: `exporter_iso3` / `importer_iso3` → `lookups/country.csv.iso3`