In Atascosa County v. Atascosa County Appraisal Dist., 990 S.W.2d 255, 258 (Tex. 1999), the county and the school district filed a challenge petition pursuant to tax code section 41.03 claiming that property owned by a previously not-for-profit hospital had been erroneously granted tax-exempt status after the hospital became a for-profit entity and sought back-appraisal for the previous five years. 990 S.W.2d at 256-57. The supreme court explained that the chief appraiser has a duty to appraise property and that tax code section 11.43(i) mandates the reappraisal of property for the years it either was excluded from taxation based on an erroneous exemption or was subject to reduced taxation based on an erroneous exemption. Id. at 257; see Tex. Tax Code Ann. 11.43(i) (West Supp. 2012) (providing that if chief appraiser discovers that an exemption has been erroneously allowed in any one of the preceding five years, he shall add the property or appraised value that was erroneously exempted for each year to the appraisal roll as provided by section 25.21). The remedy for an erroneously allowed exemption is for the chief appraiser to reappraise the property without applying the erroneous exemption and to add the erroneously exempted property or the value of the erroneously applied exemption to the appraisal roll. Tex. Tax Code Ann. 11.43(i).