China's coastal bulk freight market saw a decline in overall demand in May, data from the Shanghai Shipping Exchange (SSE) showed.

On a monthly basis, the composite index for coastal bulk freight, which measures transportation costs in the coastal shipping market, dropped 2 percent to 1,099.62.

The sub-index for coal saw the most notable decrease at 2.9 percent, followed by that for metal ore.

The sub-indices for grain and refined oil both edged up 0.4 percent, while that for crude oil remained flat from one month earlier, according to the exchange.

In 2021, the composite index for coastal bulk freight averaged 1,299.35, SSE data showed.

The SSE initiated the index in 2001 under the guidance of the Ministry of Transport to fully reflect fluctuations in the Chinese coastal transport market. ■