user: Question: What is the average expenditures on R&D for croatia after 2007?
Columns: ['Rank', 'Country/Region', 'Expenditures on R&D (billions of US$ , PPP )', '% of GDP PPP', 'Year']
Types: ['real', 'text', 'real', 'text', 'real']
Sample row: [1.0, 'United States', 405.3, '2.7%', 2011.0]
SQL:

assistant: SELECT AVG("Expenditures on R&D (billions of US$ , PPP )") FROM "Table" WHERE "Country/Region" = 'croatia' AND "Year" > 2007.0;