diff --git a/web/models/c_surveysheet_result.go b/web/models/c_surveysheet_result.go
index 2d5dce9..208f7cb 100644
--- a/web/models/c_surveysheet_result.go
+++ b/web/models/c_surveysheet_result.go
@@ -1356,7 +1356,7 @@ func (c *CSurveysheetResult) Statistic(selectType string, year string, unit stri
 
 		} else {
 			result.Building.SatisfactionPercent = utils.Decimal(float64(result.Building.ASum*5+result.Building.BSum*4+result.Building.CSum*3+result.Building.BSum*2+result.Building.ESum*1)/float64(result.Building.Count*5), 3)
-			result.Building.DifferencePercent = utils.Decimal(1-result.Building.SatisfactionPercent, 3)
+			result.Building.DifferencePercent = utils.Decimal(result.Building.SatisfactionPercent-result.Building.SatisfactionPercent, 3)
 		}
 		if result.Building.Rooms == 0 {
 			result.Building.SampleBuildingPercent = 0