My guess would be somewhere in the neighborhood of 50% or better.
Reasoning:
They make thousands every year, many of which don't get sold for many years and some not at all. The ones that do sell must carry the company.
Big distributors have pallets of scopes in the back of warehouses that have been sitting there for years...all brands.
This is true of all similar industries and products.
Only about 50% of what is placed in a big marketplace [like rifle scopes] ever actually get to the consumer...because of the competition.
There is also very stiff competition in the optics market and none of the older names are anywhere near as competitive as they were 40 or 50 years ago.
The cheap scopes from over-seas factories have forced the entire industry to trim everything they can while getting as many products on the shelves as possible.
Their only way of making a profit is by volume sales.
Therefore the mark-up from the bottom line of cost must be pretty high just to pay for being in the pipeline until it actually sells.
That's what I think based on my toe-hold understanding of the business.
BTW, about half of all Leupold scopes I've seen had to be sent back to the factory for correction. They are as-full of faults as every other brand name you care to point at.