'the highest reported' is a grammatically correct phrase and can be used in written English.
You could use it in a sentence such as: "The highest reported profit margin for the quarter was 10%."
During the past 20 years, the highest reported incidence shifted from the Americas to Africa.
The United States has the highest reported incarceration rate in the world.
This value is amongst the highest reported in the literature.
That was the highest reported microbial glycerol-to-ethanol conversion.
EPS production obtained in this work was the highest reported in the culture of T. sinense.
To the best of our knowledge, this is the highest reported value to date.
This oscillation frequency is the highest reported so far for a silicon-based transistor technology.
The value of 15 LMH for seawater desalination is the highest reported so far.
The dental ceramic with the highest reported mechanical properties is zirconia.
The erythritol productivity values we obtained here are among the highest reported thus far.
This value is one of the highest reported condensation HTCs in the literature.
