In multiregional input-output analysis, monetary flows between or within economic sectors are given in a transaction matrix T. Both, the rows and the columns, have the same index (Region 1 Sector 1, Region 1 Sector 2, ... Region 2 Sector 1, Region 2 Sector 2, ... ). The diagonal of the T matrix contains the intra-sectoral monetary flows. Analagously, the diagonal of the "regional blocks" (all sectors from one region) contains the intra-regional monetary flows between sectors.
I figured that in the database with which I am working, the share of intra-regional monetary flows (all flows belong to region 1) compared to all monetary flows of a region (all flows from region 1 to region 2 or vice versa) are rather low. Let's say around 20% on average. To me (non-expert), this seems plausible. However, I would like to crosscheck my findings with "real world data".
Question: Is there an indicator which compares intra-regional monetary flows with total extra-regional monetary flows? ... in other words: How much monetary flows between sectors take place within a country and how much monetary flows between sectors of a country take place with sectors from other countries?
I came across "Trade (% of GDP)" (https://data.worldbank.org/indicator/NE.TRD.GNFS.ZS). However, 1) in input-output analysis I understand GDP to be given by the final demand vector/matrix and 2) the given figures of about 50 to 60% are completly different to my findings of around 20%.