In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: Finally , resting and peak exercise abnormal left ventricular filling was detected in 38 and 35 % of patients as compared to 19 and 9 % of controls , respectively ( p = 0 . 11 and 0 . 02 , respectively ) .
### Output Text:
Finally , resting and peak exercise abnormal left ventricular filling was detected in 38 and 35 % of patients as compared to 19 and 9 % of controls , respectively ( p = 0 . 11 and 0 . 02 , respectively ) . 