Pratas Island was added to the list in 1994.
Pratas Island is a Taiwanese possession, and when I think of successful DX-peditions, I think of BQ9P in 2002. I had been a DX-er for one year, and worked them on all bands from 80 – 10M. They also went back in 2003, and Bob Schenk, N2OO has a nice pictorial of this trip:
Wikipedia says that Pratas Island is 211 miles southeast of Hong Kong, in the South China sea. China also claims the islands, so like Spratley and Scarborough Reef, these islands are located in a “contested” area of the world. I have heard that there are large oil fields in this part of the world, so I think the interest there goes beyond fishing – which also creates some strain in the South China seas.
Transportation to the island is very similar to the French islands Tromelin, Glorioso, Juan de Nova / Europa – by military plane only. This might explain why it isn’t activated that often.
1995 – BV9G – A DX-pedition headed by OH2BH, Martti Laine – seemingly before it was a certified entity. It was accepted by the ARRL DXCC desk however.
1995 – BV9P
1996 – April 1 – added to the DXCC list
1998 – BQ9P
2000 – BQ9P
2001 – BQ9P
2002 – BQ9P
2003 – BQ9P
I think there were more activations, but have not been able to find sources.