The net bonded indebtedness incurred for all public purposes shall not at any time exceed 10% of the assessed valuation of all the real and personal property in the city, provided that in computing such net bonded indebtedness there shall be excluded money borrowed for the following purposes: tax anticipation notes; special assessment bonds even though they are also general obligations of the city; and revenue bonds and any other obligations excluded by statute or the state constitution from such limitations.