Indian lilac vs Persian lilac

Indian lilac

noun
  • chinaberry tree (Melia azedarach) 

  • neem tree (Azadirachta indica) 

Persian lilac

noun
  • Melia azedarach, a tree in the mahogany family (Meliaceae) 

  • Syringa × persica, a shrub in the olive family (Oleaceae) 

How often have the words Indian lilac and Persian lilac occurred in a corpus of books? (source: Google Ngram Viewer )