Fewer young children have mobile phones, telecom's survey finds

Finnish telecommunications firm DNA surveyed 1,000 parents between ages of 5 to 16 years .

About a quarter of kids aged 5-6 have a phone, while 58 percent of 7-year-olds have one.

Biggest changes have occurred in the past couple of years , according to DNA's survey.

DNA advises that adult supervision of a child's use of smartphones is "always a better safeguard than age limits".