This depends on if you mean the years of application, publication, issuance, expiry and entry into the PCR of the documents you are looking for or the priority date claimed by the patent. All of these, however, work in similar ways.
Firstly, you could use the relevant boxes from the Field Search page of PatSnap:
Secondly, you could use the following addition to your query (this goes YYYYMMDD):
AND APD:[19960701 TO 20160701]
Finally, you could also use a few of the various filters that are available around the platform, for instance, if you've done a search, you can use the filters on the left-hand side to narrow down by application year:
