Removed unnecessary keywords. Strong is by default

@@ -14,6 +14,6 @@
 - (void)rollBack;
 
 @property (nonatomic) float grade;
-@property (nonatomic, strong) CAShapeLayer *chartLine;
-@property (nonatomic, strong) UIColor *barColor;
+@property (nonatomic) CAShapeLayer *chartLine;
+@property (nonatomic) UIColor *barColor;
 @end

@@ -22,13 +22,14 @@
 
 - (void)strokeChart;
 
-@property (strong, nonatomic) NSArray *xLabels;
-@property (strong, nonatomic) NSArray *yLabels;
-@property (strong, nonatomic) NSArray *yValues;
+@property (nonatomic) NSArray *xLabels;
+@property (nonatomic) NSArray *yLabels;
+@property (nonatomic) NSArray *yValues;
 @property (nonatomic) CGFloat xLabelWidth;
 @property (nonatomic) int yValueMax;
-@property (nonatomic, strong) UIColor *strokeColor;
-@property (nonatomic, strong) NSArray *strokeColors;
-@property (nonatomic, strong) UIColor *barBackgroundColor;
+@property (nonatomic) UIColor *strokeColor;
+@property (nonatomic) NSArray *strokeColors;
+@property (nonatomic) UIColor *barBackgroundColor;
 @property (nonatomic) BOOL showLabel;
+
 @end

@@ -17,14 +17,14 @@
 - (void)strokeChart;
 - (id)initWithFrame:(CGRect)frame andTotal:(NSNumber *)total andCurrent:(NSNumber *)current andClockwise:(BOOL)clockwise;
 
-@property (nonatomic, strong) UIColor *strokeColor;
-@property (nonatomic, strong) UIColor *labelColor;
-@property (nonatomic, strong) NSNumber *total;
-@property (nonatomic, strong) NSNumber *current;
-@property (nonatomic, strong) NSNumber *lineWidth;
+@property (nonatomic) UIColor *strokeColor;
+@property (nonatomic) UIColor *labelColor;
+@property (nonatomic) NSNumber *total;
+@property (nonatomic) NSNumber *current;
+@property (nonatomic) NSNumber *lineWidth;
 @property (nonatomic) BOOL clockwise;
 
-@property (nonatomic, strong) CAShapeLayer *circle;
-@property (nonatomic, strong) CAShapeLayer *circleBG;
+@property (nonatomic) CAShapeLayer *circle;
+@property (nonatomic) CAShapeLayer *circleBG;
 
 @end

@@ -21,16 +21,16 @@
 
 @property (nonatomic, retain) id<PNChartDelegate> delegate;
 
-@property (strong, nonatomic) NSArray *xLabels;
+@property (nonatomic) NSArray *xLabels;
 
-@property (strong, nonatomic) NSArray *yLabels;
+@property (nonatomic) NSArray *yLabels;
 
 /**
  * Array of `LineChartData` objects, one for each line.
  */
-@property (strong, nonatomic) NSArray *chartData;
+@property (nonatomic) NSArray *chartData;
 
-@property (strong, nonatomic) NSMutableArray *pathPoints;
+@property (nonatomic) NSMutableArray *pathPoints;
 
 @property (nonatomic) CGFloat xLabelWidth;
 

@@ -18,9 +18,9 @@
 //------------------------------------------------------------------------------------------------
 @interface PNLineChart ()
 
-@property (nonatomic, strong) NSMutableArray *chartLineArray; // Array[CAShapeLayer]
+@property (nonatomic) NSMutableArray *chartLineArray; // Array[CAShapeLayer]
 
-@property (strong, nonatomic) NSMutableArray *chartPath; //Array of line path, one for each line.
+@property (nonatomic) NSMutableArray *chartPath; //Array of line path, one for each line.
 
 - (void)setDefaultValues;