Commercial Fixed Wing
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Troubleshooting; Communication Breakdown; Situational Awareness; Confusion; Physiological - Other
Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Weight And Balance
Flight Crew Became Reoriented
Human Factors
I believe complacency played a role in this error. I am always checking and double checking my work but unfortunately I missed an important piece of information on the Center of Gravity (CG) and Passenger Count (PC) data. Next time I will slow down and thoroughly check my work without rushing and recognize my complacency.We arrived to our aircraft in the morning to perform our duties for the first leg out of two for the day. Boarding was complete and I received the cargo sheet and CG/PC Data from the gate agent. As I plugged the numbers in for departure I noticed the passenger count seemed low.  Thinking that it was due to the slow season and COVID I continued to run the numbers for our takeoff data. With the low passenger count I figured we were going to also need a ZFW reset from the dispatcher. I confirmed with the Captain and went ahead and contacted Dispatch with our new ZFW and confirmation of our CG. New numbers were sent back and we took off uneventfully.While in cruise the Captain requested a lavatory break. Upon his returned; he voiced his concern with the passenger count from what he saw in the cabin while checking our CG/PC. That is when we realized that the incorrect CG/PC was given to us. As we were starting our decent; the Captain transferred the controls to me while he referenced the COM and tables to calculate our correct weight along with the landing data and Vapp. As a precaution we also added few knots to the Vapp. The Captain completed the tasks and I confirmed that all the information was correct and within safe parameters for a safe landing.  We had sufficient runway and the field was VMC at the time of landing. The landing was uneventfully and we continued to the gate.
Air Carrier First Officer reported the pilot crew realized; in cruise; the weight and balance data were incorrect. The pilots did not question the small passenger load; which is common during the COVID-19 pandemic; before takeoff.