United have scored only 33 goals after 23 matches this campaign, which is their second worst ratio at this stage of the season in the Premier League era.
They also have the third worst conversation rate in the league, behind Hull City and Southampton.
“I understand what you are saying,” Mourinho said in his press conference on Friday.
“We attack so much and with so many players, and so many players have the freedom in our dynamic to reach scoring positions.
“I have to agree with you that we don’t score enough goals, and some of our players from these attacking creative positions they could –they should – score more goals.
“When you see the number of goals we score, there’s not a true relation between our attacking production and the number of payers we put in attacking positions and the number of goals we score.”
Speaking on United’s 0-0 draw with Hull on Wednesday, which left them four points off fourth place, Mourinho said: “We didn’t get the three points we wanted, so it’s as simple as that.
“It was a bad result for us, but we are exactly in the same position, which is try to win the next game. That is what we have done for a long time.
“Every draw we deserved a victory, We never had a draw where we could say we were lucky, or got less than what we deserved, but the reality is the reality of the points, and we lost those points.”
Mourinho added: “When you speak about Zlatan’s goals you should always add 14 goals, one penalty in 31 matches played in England, in all competitions. You should always add that extra item.
“In almost every team the striker is the top scorer – I think so – unless you have another player with a special feeling to score goals coming from another position or you have another player scoring six seven or eight goals from penalties, that is normal to happen.”