Note: Data are for public noncharter schools and are based on a count of schools, not on the total number of vacancies or the number of teachers the school failed to hire. All principals were asked whether their school has or does not have any vacancies (“teaching positions for which teachers were recruited and interviewed by this school’s hiring authority”). The shares reported in the table represent the share of schools that had any vacancies, and, for those with vacancies, the share of schools that could not fill a vacancy in at least one of the fields listed on the questionnaire, and the share of schools that filled a vacancy but found it "very difficult"  in at least one of the fields. Fields included were: (1) general elementary, (2) special education, (3) English or language arts, (4) social studies, (5) computer science, (6) mathematics, (7) biology or life sciences, (8) physical sciences, (9) ESL or bilingual education, (10) foreign languages, (11) music or art, (12) career or technical, and (13) other. With regard to teachers hired, one survey question asked principals how many teachers held full- or part-time positions in the school around the first of October for the 2015–2016 school year. Another survey question asked how many teachers at the school around the first of October were newly hired by the school and, of those newly hired teachers, how many were in their first year of teaching. The share of all teachers who were newly hired was calculated by dividing the number of teachers who were newly hired by the total number of full- and part-time teachers in each school and averaging that number across all schools responding to survey. Calculating the share of all teachers who were newly hired and in their first year of teaching follows the same process.