How to export and cite Google Ngram Viewer result?
I suggest you download this python script https://github.com/econpy/google-ngrams

This allows you to download a .csv file containing the data of your search. Then you can plot with your favourite program in your favourite format to be embedded into latex.

Concerning the .svg, it's perfect for latex, especially if you have Inkscape
https://tex.stackexchange.com/questions/151232/exporting-from-inkscape-to-latex-via-tikz