Question: How was a population  of 168375 ascertained for the Ohio county that's a namesake of Indigenous peoples of the US?
Choices: lead-lead dating
register office
estimation process
tradition
Family record booklet
Russian Empire Census
Sixth National Population Census of the People's Republic of China
2010 United States Census
national estimation
2000 United States Census
SPARQL: SELECT DISTINCT ?qpv WHERE { ?e <pred:instance_of> ?c . ?c <pred:name> "county of Ohio" . ?e <named_after> ?e_1 . ?e_1 <pred:name> "Indigenous peoples of the United States" .  ?e <population> ?pv . ?pv <pred:unit> "1" . ?pv <pred:value> "168375"^^xsd:double . [ <pred:fact_h> ?e ; <pred:fact_r> <population> ; <pred:fact_t> ?pv ] <determination_method> ?qpv .  }
Program:
function: Find
inputs: Indigenous peoples of the United States
function: Relate
dependencies: 0
inputs: named after
backward
function: FilterConcept
dependencies: 1
inputs: county of Ohio
function: QueryAttrQualifier
dependencies: 2
inputs: population
168375
determination method
Answer: estimation process