For the third year in a row, the annual energy content of the wind in Denmark in 1997 was lower than for a statistically average year, reports Vindstyrke, a monthly publication that compiles statistics of wind produced electricity in the country. Last year, the wind was logged at 91.4% of an average year, an improvement over 1996, which registered just 81.6% -- the worst since measurements began in 1979. In 1995, the wind's energy content was 95% of the average, while in the preceding nine years it was above average. The wind energy content is calculated by comparing the actual production of hundreds of wind turbines with their normal production over a period of time. The average figure resulting does not indicate the amount of wind, but the amount of usable energy in the wind.