Example query:
#defaultView:LineChart
SELECT ?year (COUNT(?person) AS ?count) WHERE {
?person wdt:P31 wd:Q5;
p:P570/psv:P570 [
wikibase:timeValue ?date;
wikibase:timePrecision ?precision
].
FILTER("1900-12-31"^^xsd:dateTime < ?date && ?date < "1910-00-00"^^xsd:dateTime).
FILTER(?precision >= 9).
BIND(YEAR(?date) AS ?year).
}
GROUP BY ?year
ORDER BY ?yearBoth axes (year and count) are numeric, which seems to be a corner case (used to summarize everything into one result, too) – in this case, both axes begin with 0, rather than a more appropriate value such as the lowest actually occurring value.
Workaround, found in the example queries: turn the X axis into a string with (STR(?year) AS ?year_).