It is less about the current importance and more about looking at the trend over time.  I am looking at whether or not the energy use of electric and electronic typewriters changed over the time period they were developed and used. 

While I cannot comment on how many typewriters are still in regular use, I have been assured by my professor, native to Chile, that typewriters are still in high demand in many countries.  I am not sure just how high that means.

Thanks for your response, and I would appreciate any other information you get over time.  It seems this data will take a while to collect.