<p><sup>a</sup> Q statistics over the entire study period 1940–2003 using year-based measure of time.</p><p><sup>b</sup> Q statistics using age-based measure of time.</p><p><sup>c</sup> Q<sub>F</sub> statistics about industries in operation from 1943 to 1999 using year-based measure of time.</p><p><sup>d</sup> The count of the number of clusters found significant at <i>α</i> ≤ 0.05.</p><p><sup>e</sup> The significance of the number of clusters found significant at <i>α</i> ≤ 0.05.</p><p>Summary of analysis results of global tests with 999 randomizations.</p
