Segments with thî: preceded by khɔ̌:ŋ "of" within a three-word window were extracted from the six writing genres of the Thai National Corpus (Aroonmanakun et al., 2009), namely fiction (which contains 7,469,530 words), newspaper (5,029,019 words), academic text (8,894,650 words), nonacademic text (5,342,092 words), law (1,190,516 words) and miscellanea (4,000,160 words).
the corpus count suggests that surrounding context can play a role in RC attachment and the bias is often but not exclusively to N1.