Cristiano Ronaldo is experiencing something of a slow start to the season.

Before you lift your pitchforks into the air, we're talking about his displays with Juventus because - by Ronaldo's lofty standards - one goal in four appearances is pretty underwhelming.

Sure, Ronaldo has a further four goals to his name this season, but we're not sure a Euro 2020 qualifier against Lithuania can be held to quite the same standards.

And while it's most certainly early days in regards to the 2019-20 campaign, Ronaldo has been struggling to reach his former goal-scoring heights throughout the calendar year as a whole.

Think we're being harsh? Well, even Ronaldo would probably be frustrated with himself because 2019 is proving to be his worst goal-scoring year since his Manchester United days.

Ronaldo's average 2019

Using data from the popular MessivsRonaldo.net, we established that Ronaldo has scored a somewhat disappointing 14 club goals in 2019.

That's less than Jamie Vardy, Moussa Dembele and Tammy Abraham have amassed in the same time period, while even Burnley's Ashley Barnes finds himself just one goal behind.

But what does that mean in the context of Ronaldo's career? Well, we trawled through the history-books to see how many goals the Portuguese had scored by September 19 each year.

Ronaldo's stats by September 19

It's then that just 14 goals really starts to look painful because Ronaldo has almost scored three times that number in the same timeframe before. Check out the full statistics down below:

2019 - 14 goals

2018 - 30 goals

2017 - 27 goals

2016 - 28 goals

2015 - 37 goals

2014 - 30 goals

2013 - 37 goals

2012 - 40 goals

2011 - 33 goals

2010 - 20 goals

2009 - 20 goals

2008 - 24 goals

2007 - 11 goals

As well as highlighting just how average Ronaldo's 2019 has been, let the statistic also illustrate just how incredible the forward was during his peak at Real Madrid.

To already be sitting on 40 goals in a calendar year by the time September rolled around is simply astonishing and suggests that even Ronaldo might be feeling the effects of ageing.

Nevertheless, there is still time for Ronaldo to turn things around before 2020 arrives and we wouldn't put it past a legend of the sport to finish the year on a high.

Sadly, however, these wilting numbers suggest that we should start to treasure Ronaldo even more while we have the pleasure of watching him each week.