That's an interesting chart, considering Zoe is actually a statistician.
She's taken all the individual points, and drawn a line through them, to represent the actual trend of those points as a straight line.
It comes out with an r value of .519.
What she never seems to say is what the 'r' value actually represents.
r is the probability the line she has assigned is the actual true representation of the trend.
So an r of .519 means she's 52% confident that she is probably correct.
And 48% confident she is probably wrong to choose this line, as a statistician.
So, in laymans terms, it's a 50/50 gamble on that line being correct.