The proportion of people dying of coronavirus who do not have underlying conditions has risen in recent weeks, from below 1% to about 5% of the total, Guardian analysis has found.

The analysis, based on daily statements released by NHS England from 5 March onwards, found that the proportion of people dying with no underlying conditions had increased sharply in the last three weeks.

Experts said the data did not suggest that the proportion of deaths in otherwise healthy individuals would continue to increase, because those already in poor health were likely to have succumbed to the disease earlier.

Germany has overseen the largest-scale coronavirus testing program in Europe, conducting 350,000 tests each week, detecting the virus early enough to isolate and treat patients effectively.

Prof Babak Javid, principle investigator at Tsinghua University School of Medicine in Beijing and consultant in infectious diseases at Cambridge University Hospitals, said the larger proportion of previously healthy people becoming infected explained the difference. “Mortality always lags, so as the pandemic was spreading, a larger proportion of the population was getting infected,” he said. “So low probability events, for example, people who are otherwise healthy dying of Covid-19, become more statistically probable.”

Eleanor Riley, a professor of immunology and infectious disease at the University of Edinburgh, said the data had become more reliable as the number of deaths had increased. “It does seem that the rate is settling at 5%-6% and I expect it will probably stay at about that rate,” she said.