It's impossible to give a clear answer to this. There are a few factors to consider:
Who is "lost"?
You may be able to find data on the number of people who are called in as missing, and where some sort of search mission is sent out to rescue them. However, not all of those people were ever at any danger of disappearing. Some may have wandered a bit off the path and then called in for a rescue themselves, others may never have been missing in the first place, but were reported as such by worried relatives.
On the other hand, there may also be people who went missing in the woods without anybody knowing about it. There are many missing person cases where it is simply not known what happened to them after they were last seen, and any number of them may well have wandered into the woods and never returned. And some people may be missing without anybody knowing they are missing at all.
There is a database of missing people in the US, called the National Missing and Unidentified Persons System. However, this does not differentiate between people who went missing in nature and who went missing under some other circumstance and were presumably abducted or fell victim to some other crime.
This article states the number of unresolved missing person cases on public land as 1,600, but that number is not based on official stats, only on research by hobbyists.
Who is "found"?
Dead people are presumably much more likely to be "found" than living people. For one thing, a living person may come back from the wilderness by their own efforts and never bother to officially inform the park authorities. A dead person will only be discovered if somebody else finds them.
The flip-side of this situation is that sometimes, the remains of a person are found in the wilderness when the person had never been reported as missing, or as missing in the wilderness. So they were "found" despite never being the object of a search or rescue mission.
You also have to consider that many people who "go missing" were never lost in the woods, but knew perfectly well where they are when they fell victim to some attack or accident. So in many cases, there was never a possibility of finding them alive in the first place. These people are exceptionally likely to be found dead, because their position is known. On the other hand, they are also often found alive, if they fail to come home at the expected time, and can be found injured or incapacitated at the site where they were expected to be - but they may not ever be counted as missing in that situation.
There is no number of missing and of found people, because neither term is very clearly defined, and no database collecting these cases exists.