Read the passage and answer the questions below.

Last month, we went to Doi Tam, a village famous for its drum making techniques, in Ha Nam Province. The craft was first introduced to the village in the 8th or 9th century. Today there are more than six hundred drum makers living in Doi Tam village. I was amazed to see big drums in front of every house in the village. People say that it takes four workers three days to make a drum with a diameter of 1.5 metres. To make a drum, the craftsmen have to follow an eight stage process. Stretching the drumhead is the most challenging stage since they have to carefully assess the sound it makes. The other steps do not require such high skills. Nowadays, Doi Tam drums are not only famous in Viet Nam but are also sold to other countries such as Laos, Cambodia, Japan, and the USA. 

When was the craft first introduced to the village?