May 20, 2014, marks the one-year anniversary of the deadly tornado outbreak in Moore, Oklahoma, which contributed to the state’s designation as the site of the costliest U.S. natural disasters in 2013, according to the Insurance Information Institute (I.I.I.).

“Oklahoma home and business owners received nearly $2 billion from their insurers, allowing them to recover economically after tornadoes changed forever communities like Moore,” said Dr. Robert Hartwig, president of the I.I.I. and an economist, in February 2014 remarks to the National Tornado Summit in Oklahoma City, Okla.

The wind speeds of the Moore tornadoes were recorded as an EF-5, the highest on the Enhanced Fujita (EF) Scale, according to the federal National Oceanic and Atmospheric Administration (NOAA). Twenty-five people, including seven children who were in school at the time, died after tornadoes touched down in and around Moore on May 20, 2013.

Besides Oklahoma ($1.99 billion), insured natural disaster-caused insurance claims payouts in 2013 were highest in Texas ($1.51 billion), Colorado ($907 million), Minnesota ($845 million) and Nebraska ($773 million).

Total U.S. natural disaster-caused insurance claims payouts came to $12.8 billion in 2013, with $10.3 billion of that figure attributable to severe thunderstorms/tornadoes, the I.I.I. found.

Indeed, Oklahoma is second only to Texas as the state with the costliest insured claims payouts resulting from thunderstorm, tornadoes and hail for the years 2000-2013, with Oklahoma cumulatively generating $9.8 billion, and Texas $16.9 billion.

An I.I.I. analysis of U.S. natural disasters dating back to 1983 found that, in any given year, 36 percent of all natural disaster-caused claims payouts arose because of tornadoes, according to Dr. Hartwig’s presentation at the National Tornado Summit.