Calculate the percentage of products supplied by Gai pturage over all products.
"Gai pturage" is the CompanyName; Percentage = Divide (Count(SupplierID where CompanyName = 'Gai pturage'), Count (SupplierID)) * 100
SELECT CAST(COUNT(CASE WHEN T2.CompanyName = 'Gai pturage' THEN 1 ELSE NULL END) AS REAL) * 100 / COUNT(T1.SupplierID) FROM Products AS T1 INNER JOIN Suppliers AS T2 ON T1.SupplierID = T2.SupplierID