Read this and answer the question. If the question is unanswerable, say "unanswerable".

Eritrea has achieved significant improvements in health care and is one of the few countries to be on target to meet its Millennium Development Goal (MDG) targets in health, in particular child health. Life expectancy at birth has increased from 39.1 in 1960 to 59.5 years in 2008, maternal and child mortality rates have dropped dramatically and the health infrastructure has been expanded. Due to Eritrea's relative isolation, information and resources are extremely limited and according to the World Health Organisation (WHO) found in 2008 average life expectancy to be slightly less than 63 years. Immunisation and child nutrition has been tackled by working closely with schools in a multi-sectoral approach; the number of children vaccinated against measles almost doubled in seven years, from 40.7% to 78.5% and the underweight prevalence among children decreased by 12% in 1995–2002 (severe underweight prevalence by 28%). The National Malaria Protection Unit of the Ministry of Health has registered tremendous improvements in reducing malarial mortality by as much as 85% and the number of cases by 92% between 1998 and 2006. The Eritrean government has banned female genital mutilation (FGM), saying the practice was painful and put women at risk of life-threatening health problems.

How many kids had been vaccinated against measles in 2008?
unanswerable