1 For public schools, the number of pupils per teacherâthat is, the pupil/teacher ratioâdeclined from 22.3 in 1970 to 17.9 in 1985.  After enrollment started increasing in 1985, the public school pupil/teacher ratio continued to decline, reaching 17.2 in 1989.
Causes. Often, a report of high blood potassium isn't true hyperkalemia. Instead, it may be caused by the rupture of blood cells in the blood sample during or shortly after the blood draw. The ruptured cells leak their potassium into the sample.This falsely raises the amount of potassium in the blood sample, even though the potassium level in your body is actually normal.When this is suspected, a repeat blood sample is done. The most common cause of genuinely high potassium (hyperkalemia) is related to your kidneys, such as:he ruptured cells leak their potassium into the sample. This falsely raises the amount of potassium in the blood sample, even though the potassium level in your body is actually normal. When this is suspected, a repeat blood sample is done.
High values. 1  High blood potassium levels may be caused by damage or injury to the kidneys. 2  High blood potassium levels can also be caused by conditions that move potassium from the body's cells into the blood. 3  Taking too many potassium supplements can also cause high levels of potassium in the blood.