the average price to rent an average apartment in Neuchâtel was 921.35 Swiss francs (CHF) per month (US$740, £410, €590 approx. exchange rate from 2003). The average rate for a one-room apartment was 451.40 CHF (US$360, £200, €290), a two-room apartment was about 675.66 CHF (US$540, £300, €430), a three-room apartment was about 825.15 CHF (US$660, £370, €530) and a six or more room apartment cost an average of 1647.88 CHF (US$1320, £740, €1050). The average apartment price in Neuchâtel was 82.6% of the national average of 1116 CHF.  The vacancy rate for the municipality, , was 0.53%.
Question: How many more US$ was a two-room apartment per month in Neuchâtel compared to a three-room apartment?
Answer: 120