Linode Network In & Out Confusion

I have a Linode 24GB which comes with 40Gbps Network In and 2,000Mbps Network Out. My server is mainly serving website content to clients and has some occasion backend processes that establish connections to external. I would like to know if the Network Out is a bottleneck in my server's performance. However, I am not too sure how to check it and confused by Linode reports.

The first I check is my Network graph under Linode dashboard. It shows 30 days result as below. I guess I should refer to Outgoing (Which seems quite low) and Incoming(Which is extremely low in Kb).
> * Priv Out => Max: 3.08Mb/s, Avg: 1.50/Mb/s, Last: 1.47Mb/s

• Priv In => Max: 174.78Mb/s, Avg: 84.11/Mb/s, Last: 69.87Mb/s

• Outgoing => Max: 12.00Mb/s, Avg: 3.83/Mb/s, Last: 2.76Mb/s

• Incoming => Max: 716.4Kb/s, Avg: 301.26/Kb/s, Last: 221.37Kb/s

However when I check my Longview -> Network Inbound & Outbound 30 days result, it shows something different. The In is much higher than the Out. Seems to me it is different measurement compare to the one above:
> * Inbound => Has occasion spike up to around 170Mb/s. But most of the time is around 50Mb/s to 100Mb/s

• Outbound => Has occasion spike up to around 25Mb/s. But most of the time is around 5Mb/s to 10Mb/s

Much appreciated if you can teach me how to check my Network In/Out actual consumption and some clarification on these network terms in Linode. Thanks! :D