Rents rose across the country in February, LSL property services revealed today. The average monthly rental price rose 0.2 per cent to £684, reflecting an annual jump of 3.9 per cent. In London rents were up 0.3 per cent in the month, yet have shot up by 7.7 per cent over the past year. The amount of unpaid rent also increased, as high unemployment and inflation continue to bite. Around one eighth (12.6 per cent) of UK rent in total was unpaid by the end of February, according to the survey.