That percentage, which is shockingly high, does not apply to the films of Louise Brooks -- at least not by much.
The actress appeared in only 14 silent films during her brief career, and only 7 of these productions are considered lost. (One of them, Just Another Blonde, is partially extant. I have seen what remains, and it looks rather fun. Another, The Street of Forgotten Men, is largely extant, but is rarely shown.) Please note, I am counting both Beggars of Life and The Canary Murder Case among Brooks' silent films, as each was released in both silent and sound versions.
All this leads me to wonder which lost Louise Brooks film YOU would most like to see. It is something to think about or even fantasize about.
If I had to pick one, I might picked Rolled Stockings, simply because Brooks likely had the most screen time in it among the lost films. Or, I might pick The City Gone Wild, because it is a gangster picture and it would be kinda cool to see Brooks as a moll. Of course, I would be thrilled to see any lost Brooks' film. Wouldn't you?
Here is a list of films featuring Louise Brooks which are considered lost. If you wish, post your pick in the comments section below.
The American Venus (1926)
A Social Celebrity (1926)
Just Another Blonde (1926) *
Evening Clothes (1927)
Rolled Stockings (1927)
Now We're in the Air (1927)
The City Gone Wild (1927)