Very few
I'm sorry to hear of your situation but it's a better than even money chance that the perpetrator will never be caught.
You say this happened "in a big city, on the East Coast of the United States". Well, New York City is one of those so I'll use their stats for illustration.
I am also unclear what you mean by "almost stabbed to death": were you robbed at knifepoint (Robbery) or were you actually stabbed (Felony Assault)?
If this happened in the week of 29 Nov through 5 Dec 2021, yours was one of 363 Robberies or 386 Felony Assaults in that week alone. Based on 2020 figures, the clearance rates (i.e. when the police decide the case is closed irrespective of the result of any trial) for these crimes were 46.8% and 66.0% respectively. That means that more than half and more than a third respectively of all those crimes in NYC from that quarter remain 'unsolved'. Most of those that are solved is because of an arrest at the scene or within 24 hours of the crime.
If all they have to go on is your verbal description of a stranger, then a) they have very little chance of ever finding them and b) they aren't going to devote many (or any) resources in trying.
Police can and do utilise all sorts of technical surveillance but they have to, for example, know whose phone to get the metadata of. They cannot, due to Constitutional protections, ask the phone company for a list of all the phones that were in a given area at a given time. If they have probable cause to believe that 555-555-5555 was the phone of the perpetrator they can seek a warrant to get the phone company to confirm where it was.