Getting your gutters cleared once a year is fairly normal, this is due to the leaves falling at the end of each year. However, if you do not have any high trees in the vicinity of your property then you could very likely push the clearing to 18-24 months. One thing to consider though is other than leaves, moss is one of the primary causes for blocked gutters. This moss comes from the roof of your property and with wind and rainfall clumps of moss will slowly fill your gutters.