Table: isaf troop number statistics
Question: Which country has the highest ratio between the number of troops and the troops per 1 billion (USD) GDP?
Step 1 (Operation, Indexing): number of troops
Step 2 (Operation, Indexing): troops per 1 billion ( usd ) gdp
Step 3 (Reasoning, Arithmetic): /, between the number of troops and the troops per 1 billion (USD) GDP
Step 4 (Reasoning, Aggregating): MAX, ratio
Answer: united states