CREATE TABLE table_201_7 (id DECIMAL, "year" DECIMAL, "gross domestic product" DECIMAL, "us dollar exchange" TEXT, "inflation index\ ( 2000 = 100 ) " DECIMAL, "per capita income\ ( as % of usa ) " DECIMAL)

what year did the kuwaiti dinar have the highest us dollar exchange ?
SELECT "year" FROM table_201_7 ORDER BY "us dollar exchange" DESC LIMIT 1
SELECT "year" FROM "table_201_7" ORDER BY "us dollar exchange" DESC NULLS LAST LIMIT 1