Private companies resident in the East Lake High-tech Development Zone -- also known as Optics Valley of China -- recently made it onto an elite list of businesses.

A total of 15 businesses in the zone -- which is located in Wuhan, capital city of Central China's Hubei province -- were selected to join the top 100 private enterprises in the province, according to a list issued by the Hubei Federation of Industry and Commerce on Oct 13.

According to local media reports, over the past five years, the entry threshold for the prestigious list has increased year by year and the requirement for the business income of the shortlisted enterprises has risen from over 1.65 billion yuan ($247.14 million) in 2015 to about 2.92 billion yuan, a gain of 76.6 percent.

In 2019, the added value of the private economy in the province reached 2.5 trillion yuan, an increase of 8.3 percent on the previous year, accounting for 54.6 percent of the province's GDP -- up 0.4 percentage points over the previous year.

A total of 19 Hubei private enterprises have entered the list of China's top 500 private enterprises in 2020, an increase of one on the previous year. The number of enterprises on the list continues to rank seventh in China and the first in Central China.