Eve Economic Data - is the Trade data released way too low?

The November 2016 Eve Online Economic Report is out - i am going through it as i write but, again, i find myself confused at the Trade data that is released.  In summary, it looks way too low to me.

The really simple explanation for this becomes apparent when i compare the Trade data to the Transaction Tax data.  As a reminder, every sale that is made on the market attracts a Transaction Tax of anywhere between 1.0% (Accounting Skill Level V) to 2.0% (no Accounting Skill).

Now, i would expect the Transaction Tax divided by the Trade data to be 1.0% because the vast majority of all Trade will be done by characters with Level V Accounting.

And indeed in February, March and April the Transaction Tax divided by the Trade data was 1.00%.

But then along came Citadels and the Transaction Tax divided by the Trade data rose at first to 1.31% and in November is now 1.69%.

That suggests to me that either the Transaction Tax data is too high or the Trade data is too low.

If i assumed that the Trade data was too low and if i assumed that the Transaction Tax divided by the Trade data was still 1.00% then i can deduce what i think the Trade data should be - see the table below:

		Stated	Transaction	Assumed		Derived
	Stated	Transaction	Tax	Tax	Derived	Citadel
	Trade	Tax	Rate	Rate	Trade	Trade
Feb	977,077	-9,817	1.00%	1.00%	977,077	0
Mar	842,974	-8,336	0.99%	0.99%	842,974	0
Apr	849,840	-8,493	1.00%	1.00%	849,840	0
May	734,239	-9,596	1.31%	1.00%	960,200	225,960
Jun	566,864	-8,068	1.42%	1.00%	807,289	240,425
Jul	514,299	-7,708	1.50%	1.00%	771,246	256,947
Aug	496,178	-7,506	1.51%	1.00%	751,086	254,909
Sep	479,205	-7,713	1.61%	1.00%	771,749	292,544
Oct	513,051	-8,520	1.66%	1.00%	852,525	339,474
Nov	596,011	-10,057	1.69%	1.00%	1,006,316	410,305

What i am doing in the above table is to take the monthly Trade Data in the first column and the monthly Transaction Tax in the second column and dividing them to get the current Transaction Tax Rate in the third column - and there you can see the problem, it is rising above 1.00% consistently.

Therefore, in the fourth column i then assume the Transaction Tax Rate stays at 1.00% and so in the fifth column i recalculate what i think the Trade data should be based on the given Transaction Tax data and this 1.00% rate.  The sixth column then takes the difference between this new Trade number and the monthly data in column 1 to give the missed Trade . . . . . and i am assuming it is the Trade done in Citadels given the Transaction Tax rate only started to deviate from 1.00% once Citadels were launched.

Or, what am i missing?

There is, of course, more to this.

Again, go back to February / March / April and the monthly ISK Volume (given in the economic report downloads) used to equal the monthly Trade data - as expected.

Again, from May onwards this relationship broke down.  However, and this is interesting, the Transaction Tax divided by the Monthly ISK Volume is now a constant 1.29%.  I can not explain that but it is interesting:

		Stated
	ISK	Transaction	Tax
	Volume	Tax	Rate
Feb	977,156	-9,817	1.00%
Mar	843,028	-8,336	0.99%
Apr	849,886	-8,493	1.00%
May	743,030	-9,596	1.29%
Jun	623,940	-8,068	1.29%
Jul	594,832	-7,708	1.30%
Aug	581,670	-7,506	1.29%
Sep	596,514	-7,713	1.29%
Oct	662,496	-8,520	1.29%
Nov	783,677	-10,057	1.28%

Eitherway, something does not add up