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: RESULTS : The percent improvements at six months were as follows : off - period score for overall motor function , 28 percent ( 95 percent confidence interval , 19 to 38 percent ) , with most of the improvement in the contralateral limbs ; off - period score for activities of daily living , 29 percent ( 95 percent confidence interval , 19 to 39 percent ) ; on - period score for contralateral dyskinesias , 82 percent ( 95 percent confidence interval , 72 to 91 percent ) ; and on - period score for ipsilateral dyskinesias , 44 percent ( 95 percent confidence interval , 29 to 59 percent ) .
### Output Text:
RESULTS : The percent improvements at six months were as follows : off - period score for overall motor function , 28 percent ( 95 percent confidence interval , 19 to 38 percent ) , with most of the improvement in the contralateral limbs ; off - period score for activities of daily living , 29 percent ( 95 percent confidence interval , 19 to 39 percent ) ; on - period score for contralateral dyskinesias , 82 percent ( 95 percent confidence interval , 72 to 91 percent ) ; and on - period score for ipsilateral dyskinesias , 44 percent ( 95 percent confidence interval , 29 to 59 percent ) . 