DVD-Subtitles?

Rating: 3/10 (2 July 2006)

The movie The World's Fastest Indian screened in Invercargill's cinemas last year. Now this DVD movie is now on sale.
As a profoundly deaf person, I really expected to have one, but to my disappointment, this does not have subtitles so I decided not to purchase.
Did the makers of this DVD movie have ignored the needs of thousands of hearing-impaired and deaf people in New Zealand? Is the next major NZ movie going to be subtitled?
I am very much appreciate if someone has the right answer.
Regards Andrew