Parsis are Zoroastrians - one of the world's oldest religions - from Persia, where it was the official religion for centuries until the advent of Islam. Persecution forced them to arrive on the shores of India over 1000 years ago where, thanks to extraordinary success in business, they have always punched above their weight, making huge contributions to Indian life.

Always a small community, their numbers have been falling relentlessly, by 10 per cent every decade since the '50s. In the 2001 census, there were only 69,000 Parsis, mostly in Mumbai. According to the latest census figures for 2011, released earlier this week, the decline has sharpened; the decade from 2001-2011 was marked by an 18 per cent fall in Parsi numbers.

It leaves just over 57,000 Parsis in India.

"We need a miracle to ensure we avoid extinction and I don't think it's coming. We will disappear into history forever and that is a painful thought," said Navjote Desai, an investment adviser in New Delhi.

Jehangir Patel, editor of the Parsi community magazine Parsiana, said the latest drop did not surprise him because the "writing has been on the wall for some time".

"Having said that, though, it was still depressing to see that the extinction is happening even faster than we thought," Patel said.

The word extinction is not an exaggeration. Quite simply, very few Parsis are being born. The Parsis closed their maternity hospital in the city a decade ago for lack of births. Patel said last year there were 800 deaths in Mumbai and 200 births.

"That is a big shortfall to fix," he said.

Parsis are dying out because they marry late, making it harder to conceive, or don't marry at all. When married, they often have only one child.

Highly Westernised in their lifestyle, many migrate to the West. Complicating matters further is the fact that the children of Parsi women who marry non-Parsis are not regarded as Parsis by the tradition-bound priesthood.

Efforts to raise the numbers have also failed to yield results. Various Parsi organisations have been exhorting young people to go forth and multiply and backing the request with money, such as help with housing for young married couples.

The Mumbai Parsi Association has been trying to persuade couples to have a second child by giving them a monthly cash payment of 3000 rupees ($60) if they have another baby. For a third baby, the cash handout rises to 5000 rupees a month.

Parsi youth organisations have tried speed dating, printing a calendar showcasing the prettiest girls in the community, and organising parties to put men and women together.

Even the government stepped in to revive the community with a special project called "Jiyo Parsi" (Keep Living Parsi) in 2013 to give subsidised IVF treatment.

Nothing, however, has worked to push up the birth rate.

The day Parsis disappear will be an immeasurable loss for India. Known as "India's Jews", famous Parsi names reverberate daily in Indian homes either because they are household names such as Tata, Godrej, or Wadia, or because of their contribution to academia, science, law, the civil service or the arts.

Queen lead singer Freddie Mercury was a Parsi, as are famous conductor Zubin Mehta and author Rohinton Mistry.

They are also known affectionately for their love of eggs. Parsis are besotted with eggs. They add eggs to everything and eat them for breakfast, lunch, tea and dinner. A well-known Parsi steel tycoon, Russi Mody, was known for having a 16-egg omelette every morning. He lived to 96.

Indians are also awed by Parsis' mysterious religious practices, such as leaving their dead to be picked clean by vultures in the Towers of Silence, a   structure in the heart of Mumbai where the eerie silence is intensified by the dark, dense encircling forest  and where only special "corpse bearers" in white clothes can set foot.

The practice arises from the Zoroastrian belief that earth, fire and water should never be contaminated by putrefying flesh.

Patel, who lives in Mumbai, is proud of the contribution the Parsis have made to their home city and to India.

"We are going to go. There really isn't any doubt about it. It's a fait accompli. But it's a shame that, after 3500 years, there will be no one left, only our legacy, but no people," he said.