We very rarely specify parameters over time for our parts. The reason for that
is because during the qualification stage of our parts, the part is submitted
to a lifetime test (generally during 1000hrs)
After this, the test program, which every single part has to pass, is designed
taking in consideration the results of the qualification stage. This means that
all the maximum parameters specified in the datasheets include a possible drift
The designer should always design with the maximum specs, and as they include
the drift over time, the performance of the design won’t change over time.