Manchester City manager Pep Guardiola said he was "a little bit grumpy" when asked about the club's January transfer business.

Rather than concentrate on City being the biggest spenders for the second consecutive winter window, he preferred to focus on net spend.

"In net spend the last five years we are seventh," Guardiola insisted.

It appeared to be targeted at critics of his team's performances this season. The Spanish manager seemed to be arguing that others have been spending more money to catch up.

"They are facts," Guardiola added. "Good luck to the six teams who are in front of us for net spend for the last five years."

Figures from Footballtransfers.com show City are sixth, not seventh, with a net spend of £324.7m.

But let's be fair to Guardiola. He is effectively correct.

Nottingham Forest (£323m) pretty much have the same net spend despite being in the Championship for the first season of the calculation.

But is it as straightforward as this for City?

There are two ways of looking at things.

Yes, City are not the biggest net spenders.

But the data also shows they have spent the second most on players over this period.

Chelsea have spent the most (£1.57bn) to try to catch up with the likes of Manchester City. They have sold the most, too, with £862m worth of talent.

Guardiola comes second on both: £962.3m spent with £637.6m brought in from sales.

This underlines how City have been incredibly adept at bringing through players from their academy and selling them for high transfer fees. In fact around £280m has been recouped in this way in the last five years.

Cole Palmer moved to Chelsea for £40.9m. James McAtee was signed by Forest in a £22.2m deal. Taylor Harwood-Bellis switched to Southampton for £20m.

Between them they made six Premier League starts for City, yet all three appear as pure profit as club-trained players.

This is not a criticism, though. It is exactly how an academy should operate.

If a player is not to the level of the first team, or has limited opportunities, then they should be sold. Rinse and repeat the process as the years pass.

But it could be construed as creating a slightly misleading picture in terms of net spend on the first team.

Chelsea have the same kind of model so it should be no surprise that their finances are along similar lines. It is just to slightly different levels.

Manchester United have the worst of all worlds: a high spend, a low return in transfers and disappointing results on the pitch.

The Red Devils are third in spending (£920.9m) but they have not come close to utilising the value of their academy, with player sales of just £246.6m.

That places them second in net spend (£674.3m).

This could also be said of Arsenal, who are third in net spend (£610.1m) but they have the lowest outgoing sales of the top clubs - just £184.2m.

But of course the Gunners sit clear at the top of the Premier League. Their incoming transfer business of £743.9m has been more effective than Manchester United's.