Use if you want. This is just the moving command for the example. Teachers lost 15 percent of their wages to inflation since the 1991-92 school year. All the statements could be true, depending on how the impact of inflation on teacher salaries is calculated. The only exception may be the first one, an assertion of the Washington Education Association.
Statistics can be misleading.
In this case, one can use statistics to maximize or minimize the loss in teachers' salary. For example, the Seattle CPI used by the WEA to calculate losses in teacher salaries tends to exceed other commonly used measures of inflation, thus exaggerating the impact of inflation on teachers statewide. When teachers' pay is discussed, the total package must be considered as well. A reasoned discussion about teacher compensation requires a straightforward understanding about teachers' complete salary packages. The current system rewards the best and worst teachers equally.