However, regarding total forest cover, Vietnam has undergone a forest transition: its forest cover has increased since the early 1990s, after decades of deforestation.[4] As of 2005, 12,931,000 hectares (the equivalent of 39.7% of Vietnam's land cover) was forested, although only 85,000 hectares (0.7% of the land cover) was primary forest, the most biodiverse form of forest.[5]