Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE festival_detail (YEAR VARCHAR, LOCATION VARCHAR)
### Question:
In which year are there festivals both inside the 'United States' and outside the 'United States'?
### Answer:
SELECT YEAR FROM festival_detail WHERE LOCATION = 'United States' INTERSECT SELECT YEAR FROM festival_detail WHERE LOCATION <> 'United States'