E-commerce comprised 5% of total retail.
This chart from Credit Suisse shows that Singapore falls behind China, US, and Japan in terms of e-commerce usage.
In 2017, Singapore e-commerce comprised 5% of the country's total retail.
Meanwhile, e-commerce comprised 23% of total retail in China and 8% of retail in the US.
Singapore still beat other ASEAN countries, however. The proportion of e-commerce in total retail in Indonesia is at 3%, nearly 2% in Malaysia and Thailand, and 1% in Vietnam and the Philippines.