I see 3 semi-distinct bands in the data, where there are dense clusters of lines, and gaps in between where the lines are a bit more sparse. It looks to me like the line jumps from the bottom band to the middle band in 1997, then back down, then up again in 2001, and then stays there until 2014/2015 when it jumps up a second time. You can see them better if you remove the mean/+2sigma/-2sigma lines. I wonder the reason for that? Could be I'm just seeing patterns where none exist of course.

Edit: the jumps kind of correspond to moments in time when the solar insolation was on its upswing and the periods when it temporarily slowed kind of correspond to periods when insolation was declining, I think however I'm exceeding my training a bit, perhaps an actual climate scientist could tell us more precisely what's going on.