In what year was the well known Indian athlete whom O. M. Nambiar coached born?
O. M. Nambiar:  He coached the well known Indian athlete P. T. Usha. P. T. Usha: Pilavullakandi Thekkeparambil Usha (born 27 June 1964), popularly known as P. T. Usha, is a retired Indian track and field athlete.
1964