Update README.md

minor fix in example usage

README.md

@@ -193,7 +193,7 @@ We can specify different area range levels, at which we would like to compute th
 >>> print(result)
 {'all': 
     {'range': [0, 10000000000.0],
-    'iouThr': '0.00',
+    'iouThr': '0.9',
     'maxDets': 100,
     'tp': 0, 
     'fp': 3,
@@ -208,7 +208,7 @@ We can specify different area range levels, at which we would like to compute th
 }, 
 'small': {
     'range': [0, 36],
-    'iouThr': '0.00',
+    'iouThr': '0.9',
     'maxDets': 100,
     'tp': 0,
     'fp': 1,
@@ -223,7 +223,7 @@ We can specify different area range levels, at which we would like to compute th
 }, 
 'medium': {
     'range': [36, 144],
-    'iouThr': '0.00',
+    'iouThr': '0.9',
     'maxDets': 100,
     'tp': 0,
     'fp': 2,
@@ -237,7 +237,7 @@ We can specify different area range levels, at which we would like to compute th
     'nImgs': 2
 }, 'large': {
     'range': [144, 10000000000.0],
-    'iouThr': '0.00',
+    'iouThr': '0.9',
     'maxDets': 100,
     'tp': -1,
     'fp': -1,