Wikipedia:As of

The "as of" technique is a method to deal with information that will quickly become dated. Some articles have information that is valid only at a specific moment in history, such as population statistics and current events. If you suspect that a fact in an article will become dated at some point in the future, and want to ensure that people will update it, include a tag of the form

{{As of|year}} or {{As of|year|month}}

with the year of validity in place of year and the month number in place of month. See the {{As of}} template for additional options and detailed examples.

Every individual, non-contiguous statement in an article that may date quickly should be so tagged, even if there are several such statements that link to the same year. Otherwise, it is possible that when one statement is updated, other statements in the article might be overlooked, and no one will realize that they need to be checked also.