Section 4. Real Property Taxation

(a) Except as otherwise provided in this Section, taxes upon real property shall be levied uniformly by valuation ascertained as the General Assembly shall provide by law.
(b) Subject to such limitations as the General Assembly may hereafter prescribe by law, counties with a population of more than 200,000 may classify or to continue to classify real property for purposes of taxation. Any such classification shall be reasonable and assessments shall be uniform within each class. The level of assessment or rate of tax of the highest class in a county shall not exceed two and one-half times the level of assessment or rate of tax of the lowest class in that county. Real property used in farming in a county shall not be assessed at a higher level of assessment than single family residential real property in that county.
(c) Any depreciation in the value of real estate occasioned by a public easement may be deducted in assessing such property.