July 1 (Reuters) - Workers identifying as "Black+" or "Latinx+" left Alphabet Inc"s (GOOGL.O) Google at higher rates last year than in 2019, the company said on Thursday in its latest annual diversity report, highlighting a persistent challenge to growing representation. What Google calls an attrition index, with 100 as a baseline, registered at 121 last year for Black+ workers in the United States compared with 112 in 2020. For Latinx+ employees, it jumped to 105 last year from 97. Attrition soared to 146 from 110 for Black+ women, though it fell to 81 from 93 for Latinx+ women. For White+, attrition dropped to 112 from 117, falling across both men and women. Google last year committed to increasing retention of racial minorities and other groups by increasing support staffing and programs. But some people from underrepresented backgrounds have said they continue to feel unwelcome in the tech industry, and they also remain high in demand elsewhere as companies compete to increase diversity. Google declined to comment beyond its new report, which noted room for improvement in retaining underrepresented talent but added some new training and practices are showing promising results. Civil rights groups and activist investors are pressuring Silicon Valley companies such as Google to bring more women and racial minorities into leadership, contending that better business results would follow. Google did make some strides. The company nearly doubled the number of Black+ people in U.S. leadership to 7.1% last year and increased the number of women globally in leadership to 28.9% from 26.1%. Last year was its best since it began reporting data in 2014 for hiring of Black+ and Latinx+ U.S. workers, with 8.8% of overall hires coming from each of those groups compared with 5.5% for Black+ in 2019 and 6.6% for Latinx+. Still, just 1.8% of technology hires were Black+ women and an equal share Latinx+ women.