public java.util.List<String> getAdditionalStatistics() {
        if (additionalStatistics == null) {
            additionalStatistics = new com.amazonaws.internal.SdkInternalList<String>();
        }
        return additionalStatistics;
    }
<p>
The list of additional statistics that are to be streamed for the metrics listed in the
<code>IncludeMetrics</code> array in this structure. This list can include as many as 20 statistics.
</p>
<p>
If the <code>OutputFormat</code> for the stream is <code>opentelemetry1.0</code> or <code>opentelemetry0.7</code>
, the only valid values are <code>p<i>??</i> </code> percentile statistics such as <code>p90</code>,
<code>p99</code> and so on.
</p>
<p>
If the <code>OutputFormat</code> for the stream is <code>json</code>, the valid values include the abbreviations
for all of the statistics listed in <a
href="https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/Statistics-definitions.html.html">
CloudWatch statistics definitions</a>. For example, this includes <code>tm98, </code> <code>wm90</code>,
<code>PR(:300)</code>, and so on.
</p>

@return The list of additional statistics that are to be streamed for the metrics listed in the
        <code>IncludeMetrics</code> array in this structure. This list can include as many as 20 statistics.</p>
        <p>
        If the <code>OutputFormat</code> for the stream is <code>opentelemetry1.0</code> or
        <code>opentelemetry0.7</code>, the only valid values are <code>p<i>??</i> </code> percentile statistics
        such as <code>p90</code>, <code>p99</code> and so on.
        </p>
        <p>
        If the <code>OutputFormat</code> for the stream is <code>json</code>, the valid values include the
        abbreviations for all of the statistics listed in <a
        href="https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/Statistics-definitions.html.html">
        CloudWatch statistics definitions</a>. For example, this includes <code>tm98, </code> <code>wm90</code>,
        <code>PR(:300)</code>, and so on.
aws-java-sdk-cloudwatch/src/main/java/com/amazonaws/services/cloudwatch/model/MetricStreamStatisticsConfiguration.java