In 2007, about 36% of the work force was employed in manufacturing (22.8%) and construction (10.4%), compared with the national average of 23% (see Table 1.5. Salary levels are relatively low: in 2005 the average monthly income in the Northern District was NIS 6 000 (NIS 6 887 for men and NIS 4 657 for women), compared with the national average of NIS 7 054 (8 575 for men and 5 419 for women) (see Figure 1.3. Income per capita in the Northern District is approximately 47% lower than in the Tel-Aviv metropolitan area (see Figures 1.4. Between 2006-07, 300 000 people migrated to the region while 329 000 left the region.