We have so far converted 600 pre-TN industries (yielding one point each of construction, mining and fuel refining) to 300 TN mines and 300 TN construction factories (each yielding 10 points of their particular specialty). The rate of conversion is accelerating as our construction capability grows, and I have started interspersing these builds with an occasional research lab, in an effort to speed up our lamentably slow research. Five years into the game, we are still researching our third tech (+20% to mining rate).