line chart to attach all points

[researcy]

I'm entering data by time every half hour. For some time periods, there are no entries. I want a line chart to show the variation of the numbers throughout the day, but if I skip a time period the points on the chart are no longer connected by a line. You can see the missing lines in the attachment. This is a line chart, should I be doing something different or use a different type of chart?

[researcy]

Attachment.