Systole is the last stage of a heart beat. It happens right after diastole, when the heart refills with blood. During systole, the heart's two ventricles contract (squeeze). (The ventricles are the largest parts of the heart, which pump blood to the body and lungs.) During systole, the heart muscle gets an automatic electrical signal that tells the heart to contract (squeeze). This makes the blood flow out of the heart.
Basics. General contractors earned a mean $45.14 per hour, or $93,900 per year, as of May 2011, according to the Bureau of Labor Statistics. The lowest-paid 10 percent of contractors received less than $24.35 per hour, or $50,650 per year, while the best-paid 10 percent made $71.67 per hour, or $149,070 per year.
Some contracting outfits charge there customers up to $600 for a single installer per day to $1200 per day for an installation crew and hire independent contractors to do the job. Paying them a commission of 40 to 70% of the jobs total installation cost depending on their reliability and completion time.