businesses engaged in the new economy. For years ended December 31, 2018, 2019 and 2020 and the six months ended June 30, 2020 and 2021, our number of agents was 4,608, 7,213, 9,128, 7,473 and 10,020, respectively. In the years ended December 31, 2018, 2019 and 2020 and in the six months ended June 30, 2020 and 2021, we generated revenue of S$181.2 million, S$330.3 million, S$434.7 million, S$209.3 million and S$251.6 million, respectively.
The rapid growth which we have experienced requires us to constantly monitor, evaluate and, if appropriate, reallocate our management and financial and operational resources. In order to manage growth effectively, we must recruit new employees, including employees in middle-management positions such as team leader roles, and implement and improve operational systems, procedures and internal controls on a timely basis.
In addition, we need to update our existing internal accounting, financial and cost control systems to ensure that we can access all necessary financial information in line with the increasing demands of our business. Any internal and disclosure controls and procedures, no matter how well conceived and operated, can provide only reasonable, but not absolute, assurance that the objectives of the control system are met. The design of a control system must consider the benefits of controls relative to their costs. Inherent limitations within a control system include the realities that judgments in decision-making can be faulty, and that breakdowns can occur because of simple errors or mistakes. Additionally, controls can be circumvented by individuals acting alone or in collusion with others to override controls, which may also include controls implemented by our clients. If we are unable to assert that our internal controls over financial reporting are effective now or in the future, or if our auditors are unable to express an opinion on the effectiveness of our internal controls, we could lose investor confidence in the accuracy and completeness of our financial reports.
If we fail to implement these systems, procedures and controls or update these systems on a timely basis, we may not be able to service our clients’ needs, hire and retain new employees, pursue new business, complete future acquisitions or operate our business effectively. Failure to effectively transfer new client business to our delivery centers, properly budget transfer costs, accurately estimate operational costs associated with new contracts or access financial, accounting or cost control information in a timely fashion could result in delays in executing client contracts, trigger service level penalties or cause our profit margins not to meet our expectations. Any of the foregoing factors could adversely affect our business, financial condition and results of operations.
If we fail to implement and maintain an effective system of internal controls, we may be unable to accurately or timely report our results of operations or prevent fraud, and investor confidence and the market price of our ADSs may be materially and adversely affected.
Prior to this offering, we were a private company with limited accounting personnel resources. Furthermore, prior to this offering, our management has not performed an assessment of the effectiveness of our internal control over financial reporting, and our independent registered public accounting firm has not conducted an audit of our internal control over financial reporting. Effective internal control over financial reporting is necessary for us to provide reliable financial reports and, together with adequate disclosure controls and procedures, are designed to prevent fraud.
Our internal controls relating to financial reporting have not kept pace with the expansion of our business. Our financial reporting function and system of internal controls may be less developed in certain respects than those of similar companies that operate in fewer or more developed markets and may not provide our management with as much or as accurate or timely information. The Public Company Accounting Oversight Board, or PCAOB, has defined a material weakness as “a deficiency, or a combination of deficiencies in internal control over financial reporting, such that there is a reasonable possibility that a material misstatement of the annual or interim statements will not be prevented or detected on a timely basis.”
In the course of auditing our consolidated financial statements as of and for the years ended December 31, 2018, 2019 and 2020, we and our independent registered public accounting firm identified three material weaknesses in
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