That's not exceptional at all: it is the standard presence requirement that one is present in New Zealand with the right to remain indefinitely for a minimum of 1,350 days in the five years preceding the citizenship application, and for at least 240 days in each of the five years. The Citizenship Office calculates presence from the date that they receive your completed application, together with the required fee.
An individual who never or rarely travels out of New Zealand may therefore meet this requirement before 5 years from the grant of a Resident Visa has elapsed: someone who never travels out of New Zealand will meet the standard presence requirement after precisely 4 years and 240 days since the grant of their Resident Visa.
It is not able to give you a definite answer without knowing your exact travel history, but since the Citizenship Office works backwards from your application being received and paid for, you should do the same. Pick the date that you are likely to lodge your application, then look at each of the five year periods prior (so, if you plan on lodging your application on 2021-04-20, look at 2020-04-21 to 2021-04-20, 2019-04-21 to 2020-04-20, etc.), then add up the days you have been present in New Zealand (inclusive of arrival and departure dates, but exclusive of periods where you have not held a residence class visa). Each of those 5 periods must come to 240 days or more, and the sum of all of those 5 periods must come to 1,350 days or more.
If you have any doubt as to your travel history, you may
request the records that Immigration New Zealand holds of your travel movements. The Citizenship Office will base their assessment of you meeting the presence requirement on these same records.
The "exceptional cases" requirement allows the applicant to only have been in New Zealand for at least 450 days in the 20 months immediately preceding the date of application and have held New Zealand residence for that whole period. This reduction of the presence requirement is only applied when the applicant's situation is well outside the normal run of circumstances found in citizenship grant cases generally; the circumstances do not have to be unique or very rare, but they do have to be truly an exception rather than the rule, or they would need to be out of the ordinary and comparatively rare. If you believe that you have exceptional circumstances that merit consideration for a reduction of the presence requirement, you should contact the Citizenship Office to discuss your situation.