To answer the essencespirit of thisthe question, the ordinal numbers in such a construct of that type should be interpreted like this:
It'sIt is the sixth year [in progress] now [of[since the stated event], i.e. five5 full years and into+ part of the current year.
Another typical example:
Маше уже восьмой год пошёл.
Masha is in her eighth8th year (of life), i.e. she'sshe is seven-and-a-bit years old and counting/going on eight.