When additional taxes are voted for by the people, an individual's property tax bill will increase. Also, when market value increases, naturally, so does the assessed value. If you were to make improvements to your existing property, for instance, add a garage, or an additional room, the "fair market value" increases, and therefore, the assessed value would also increase. The assessor has not created the value. People make the value by their transactions in the marketplace. The assessor simply has the legal and moral responsibility to study those transactions and assess your property accordingly. 

Even if you do not receive a tax notice, it is your responsibility to be sure that the property taxes have been paid. You may contact the appropriate tax collector to determine the amount of property taxes owed and whether or not the taxes have been paid.