So you think Jakob has only 60% chance for ever being in the same shape as last year IN THE REST OF HIS CAREER?!
I would - barring serious illness or injury - give him 80% chance that he will be in significant better shape later in his career than last year.
That is how it goes when you are 22 years old and are training under a well proven, well balanced, mainly aerobic training regimen: You improve your aerobic capacity and therefore your times gradually as time goes by.