center div if one or more than one

.team_outer_sec ul li{
width:25%;
}
.team_outer_sec ul li:nth-last-child(1){
margin-left: 37.5%;
}
.team_outer_sec ul li:nth-last-child(2){
margin-left: 25%;
}
.team_outer_sec ul li:nth-last-child(2) ~ li{
margin-left:0;
}
.team_outer_sec ul li:nth-last-child(3){
margin-left: 12.5%;
}
.team_outer_sec ul li:nth-last-child(3) ~ li{
margin-left:0;
}
.team_outer_sec ul li:nth-last-child(4) ~ li{
margin-left:0;
}