Its value was the lowest at the end of 2008 and in the first half of 2009, it increased in the next years, declined in 2012 and from 2013 on it has been growing again.
Vrednost tega kazalnika je bila najnižja konec 2008 in v prvi polovici 2009, v naslednjih letih se je zvišala, v 2012 je ponovno padla, od 2013 pa spet narašča.