Modern Lithuanian education system has multiple structural problems. Insufficient funding, quality issues, and decreasing student population are the most prevalent. Lithuanian teacher salaries are the lowest in the entire EU. Low teacher salaries was the primary reason behind national teacher strikes in 2014, 2015, and 2016. Salaries in the higher education sector are also low. Many Lithuanian professors have a second job to supplement their income. PISA report from 2010 found that Lithuanian results in math, science and reading were below OECD average. PISA report from 2015 reconfirmed these findings. The population ages 6 to 19 has decreased by 36% between 2005 and 2015. As a result, the student-teacher ratio is decreasing and expenditure per student is increasing, but schools, particularly in rural areas, are forced into reorganizations and consolidations. As with other Baltic nations, in particular Latvia, the large volume of higher education graduates within the country, coupled with the high rate of spoken second languages is contributing to an education brain drain.