Was a company 's Mexican employee employed by M0
SELECT count(*) WHERE {
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company ?x1 .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M0 .
?x0 ns:people.person.nationality ns:m.0b90_r .
?x1 a ns:business.employer
}