Among all chemical compounds that contain molecule TR047, identify the percent that form a double-bond.
TR047 is the molecule id; double bond refers to bond_type = ' = '; percentage = DIVIDE(SUM(bond_type = ' = '), COUNT(all bond_id)) as percent where molecule_id = 'TR047'
SELECT CAST(COUNT(CASE WHEN T.bond_type = '=' THEN T.bond_id ELSE NULL END) AS REAL) * 100 / COUNT(T.bond_id) FROM bond AS T WHERE T.molecule_id = 'TR047'