Damages from severe thunderstorms have been growing at a much faster rate than all other weather events over the past quarter century, according a report released Wednesday by Swiss Re.

Global insured losses from what Swiss Re called severe convective storms rose by an average annual rate of 9 percent during the period from 1990 to 2014.

The world's number two reinsurer said the term covers tornadoes, hail, thunder, heavy rains and flash floods.

Meanwhile insured losses from all weather events rose by an average annual rate of 6.6 percent during the same period.

In the United States alone, it said insured damages from severe storms averaged $8 billion over the 25-year period, but since 2008 they have exceeded $10 billion every year.

Last year, they came in at $13 billion.

The year 2014 was an unusual year, in that 189 natural catastrophes occurred worldwide, the highest in Swiss Re's records, but loss of life and property were lower.

Around 12,700 people lost their lives in last year's disaster events, less than half as many as in 2013, making it one of the lowest numbers ever recorded in a single year.

Total economic losses came in at $110 billion, down from $138 billion in 2013, and well below the previous 10-year annual average of $200 billion.

Nations are trying to limit the rise in global temperatures to two degrees Celsius (3.6 degrees Fahrenheit) over pre-Industrial Revolution levels, with scientists fearing further increases may result in more extreme weather phenomena in addition to harming agricultural production.