How to center 2 rows with flexbox?

Hello I have the following bit of code but i'm struggling to sort out a layout issue. Ideally i would like the rows to go from left to right as shown in the picture but I would like to center the entire structure.

Currently have

But I would like this

This is the css and code i'm currently using.

<div class="service_list_container">
            <div class="service_tab"></div>
            <div class="service_tab"></div>
            <div class="service_tab"></div>
            <div class="service_tab"></div>
            <div class="service_tab"></div>
        </div>

.service_list_container {
    background: blue;
    display: flex; /* or inline-flex */
    flex-wrap: wrap;
    justify-content: space-evenly;
}

.service_tab {
    flex-basis: 300px;
    flex-grow: 0;
    flex-shrink: 0;
    height: 400px;
    background: #fff;
    margin: 10px 20px;
    -webkit-box-shadow: -2px -1px 5px 0px #efefef;
    -moz-box-shadow: -2px -1px 5px 0px #efefef;
    box-shadow: -2px -1px 5px 0px #efefef;
    border: solid 1px #e8e8e8;
}

Is it possible using flexbox to achieve what I am after? Thanks