  Here, we show that the detection of Borisov implies that interstellar objects
outnumber Solar system objects in the Oort cloud, whereas the reverse is true
near the Sun due to the stronger gravitational focusing of bound objects. This
hypothesis can be tested with stellar occultation surveys of the Oort cloud.
Furthermore, we demonstrate that $\sim 1 \%$ of carbon and oxygen in the Milky
Way Galaxy may be locked in interstellar objects, saturating the heavy element
budget of the minimum mass Solar nebula model.
