Are batting collapses becoming more common?

From a very good analysis of the surge in batting collapses at a time when batsmen are piling on the runs, these statistics stand out

Test teams are scoring huge totals much more often than they used to. Between 1960 (more or less the start of the current era of covered pitches) and the end of 1999, one in 18 innings would see a team rack up 500 or more. Since the start of 2000, that rate has almost doubled to one in ten. Last year, teams amassed 500 or more on 19 occasions: one in nine... sub-100 totals have also become much more frequent. From 1960 until 1999, the dreaded double-figures dig happened roughly once every 70 innings. Since 2000, that figure has jumped to one in 47... In the 1950s, the average sub-100 innings lasted 293 deliveries. Since then, the carnage has accelerated. In the 1960s, the average rout lasted 255 balls; in the 1990s, 221. Since 2010 it has taken an average of just 184 balls to end the misery. That's a full 18 overs fewer than 60 years ago.

Tim Eaton appears to trace the failing to the technical weaknesses of the No 6 batsmen (bully instead of being a bulwark, as he writes), especially for Australia and South Africa, the two countries surprisingly vulnerable to such collapses. The dominance of seam bowlers in the list of those responsible for such collapses is interesting and highlights the effectiveness of late movement. 

While those may be contributors, I am inclined to the argument that the defensive technique and temperaments of modern batsmen may be responsible. One way to statistically verify it may be to see how many of these wickets fell to defensive and attacking shots respectively over the different periods. My hunch is that getting out attacking the ball would predominate in recent years.

Also, we need to discount the much more number of tests being played in recent years, with more tours and more teams. It is now not uncommon to have players playing 100 tests over a 7-10 year career, something which would have taken twice that many years before the millennium. 

It may also be useful to do an examination of whether batting collapses in general have increased in recent years. If we assume losing 5 wickets for an addition or 10 runs or 8 wickets for an addition of 30 runs as collapses, is there an increasing trend of such collapses?