The Morteratsch Glacier in Switzerland has had one of the longest periods of scientific study with yearly measurements of the glacier's length commencing in 1878. The overall retreat from 1878 to 1998 has been with a mean annual retreat rate of approximately per year. This long-term average was markedly surpassed in recent years with the glacier receding per year during the period between 1999 and 2005. Similarly, of the glaciers in the Italian Alps, only about a third were in retreat in 1980, while by 1999, 89% of these glaciers were retreating. In 2005, the Italian Glacier Commission found that 123 glaciers in Lombardy were retreating. A random study of the Sforzellina Glacier in the Italian Alps indicated that the rate of retreat from 2002 to 2006 was much higher than in the preceding 35 years. To study glaciers located in the alpine regions of Lombardy, researchers compared a series of aerial and ground images taken from the 1950s through the early 21st century and deduced that between the years 1954–2003 the mostly smaller glaciers found there lost more than half of their area. Repeat photography of glaciers in the Alps indicates that there has been significant retreat since studies commenced.