Open Archives API » Related/Census

Retrieve census data of Dutch place/municipality for year nearest to specified year.

Data sources used for this service:

• Volkstellingen.nl (the census date), by DANS
• Gemeentegeschiedenis.nl (places from census are linked to this source)

URL

https://api.openarchieven.nl/1.0/related/census.json

Method

GET

Input

Name	Required	Description	Default
year	Yes	A number between 1770 and 1980 (inclusive). Based on the year, the nearest census will be chosen from the available censusses: 1795, 1830, 1840, 1849, 1859, 1869, 1879, 1889 and 1899 (in near future 1909, 1920, 1930, 1947 and 1971 will be added).
place	Yes*	The name of the place (case-insensitive) from which census data is requested. If a place name is given as well as an gg_uri, only the gg_uri will be used (* either place or gg_uri is required).
province	No	The name of the province (case-sensitive) to narrow down the search on place. Beware that the province names are stored as they were in the census, so besides current Groningen and Overijssel, you also have Holland, Bataafsch Braband and Vriesland.
gg_uri	Yes*	The Gemeentegeschiedenis URI (case-sensitive) of the municipality from which census data is requested, eg. http://www.gemeentegeschiedenis.nl/gemeentenaam/Leiden (* either place or gg_uri is required). Beware that not all places have been mapped to a Gemeentegeschiedenis URI, only about 85%.
richness	No	Value indicating the level of information provided: 1 - only basic information and population number 2 - like 1, plus all available census data 3 - like 2, plus aggragated data about provinces	1
callback	No	Function name to be called on JSON data (JSONP).

Output

The output is in JSON. It's an array of hashes with census data (of max 10 places). Each field within these hashes has a value and an descriptive label. As each census was different, the set of data points differs as well. Because the order of the orginnal columns has meaning too, the column fieldnames are prepended with the column number.

Example: https://api.openarchieven.nl/1.0/related/census.php?year=1840&place=leiden&richness=3 outputs (pretty-printed):

{
	"census": [
		{
			"population": 37464,
			"gg_uri": "http:\/\/www.gemeentegeschiedenis.nl\/gemeentenaam\/Leiden",
			"table": {
				"02 huizen": 6300,
				"03 huisgezinnen": 7859,
				"04 ongehuwde mannen": 11085,
				"05 gehuwde mannen": 5943,
				"06 weduwnaars": 578,
				"07 mannen": 17606,
				"08 ongehuwde vrouwen": 11943,
				"09 gehuwde vrouwen": 6034,
				"10 weduwen": 1881,
				"11 vrouwen": 19858,
				"12 inwoners": 37464,
				"13 protestanten": 27068,
				"14 rooms-katholiek": 9927,
				"15 isra\u00c3\u00abliten": 427,
				"16 niet genoemde gezindheden": 42
			},
			"name": "Leiden",
			"province": "Zuid-Holland",
			"year": 1840
		}
	],
	"totals": {
		"Noord-Braband": 378437,
		"Gelderland": 345762,
		"Zuid-Holland": 526020,
		"Noord-Holland": 443334,
		"Zeeland": 151358,
		"Utrecht": 145132,
		"Vriesland": 227859,
		"Overijssel": 197694,
		"Groningen": 175651,
		"Drenthe": 72484
	}
}

Errors

One of the following errors may be thrown:

Error code	Error message
35	Invalid year (>=1770 and =<1980)
38	Invalid gg_uri (should start with http://www.gemeentegeschiedenis.nl/gemeentenaam/)
36	Missing required year
37	Missing required place or gg_uri

An example error looks (pretty-printed) like:

{
	"error_code": 4,
	"error_description": "Invalid lang"
}

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