Rotated tekst not properly aligned with tablepress

Hello,
I’m using tablepress 1.6.1 to show an expertise matrix with in the first column the expertise of employees and en in the first row the employee names. The expertise is split in several knowledge area’s and before the start of a knowledge area i again have a row with their names.

I was able to get the names rotated 90 degrees, but i don’t get them properly aligned. I looks like that short named are more aligned to the left and that the length of the name makes them more shifted to the right.

I would like to have all the names centered in a cell, or horizontally centered and vertically aligned to the bottom.

Please tell me what i do wrong.

I have following css code:
/* Geberal Settings */
.tablepress-id-1 {
font-size: 12px;
border: 1px solid #AAAAAA;
table-layout: fixed;
}

.tablepress-id-1 .column-1 {
width: 150px !important;
text-align: left;
}

.tablepress-id-1 .column-2 {
width: 30px !important;
}

.tablepress-id-1 .column-3 {
width: 30px !important;
}

.tablepress-id-1 .column-4 {
width: 30px !important;
}

.tablepress-id-1 .column-5 {
width: 30px !important;
}

.tablepress-id-1 .column-6 {
width: 30px !important;
}

.tablepress-id-1 .column-7 {
width: 30px !important;
}

.tablepress-id-1 .column-8 {
width: 30px !important;
}

.tablepress-id-1 .column-9 {
width: 30px !important;
}

.tablepress-id-1 .column-10 {
width: 30px !important;
}

.tablepress-id-1 .column-11 {
width: 30px !important;
}

.tablepress-id-1 .column-12 {
width: 30px !important;
}

.tablepress-id-1 .column-13 {
width: 30px !important;
}

.tablepress-id-1 .column-14 {
width: 30px !important;
}

.tablepress-id-1 .column-15 {
width: 30px !important;
}

.tablepress-id-1 .column-16 {
width: 30px !important;
}

.tablepress-id-1 .column-17 {
width: 30px !important;
}

.tablepress-id-1 .column-18 {
width: 30px !important;
}

.tablepress-id-1 .column-19 {
width: 30px !important;
}

.tablepress-id-1 .column-20 {
width: 30px !important;
}

.tablepress-id-1 .column-21 {
width: 30px !important;
}

.tablepress-id-1 .column-22 {
width: 30px !important;
}

/* Body */
.tablepress-id-1 tbody td {
border: 1px solid #AAAAAA;
text-align: center;
vertical-align: middle;
}

/* Row 1 – Specialists */
.tablepress-id-1 .row-1 span {
font-size: 14px;
-webkit-transform: rotate(-90deg);
-moz-transform: rotate(-90deg);
-ms-transform: rotate(-90deg);
-o-transform: rotate(-90deg);
height: 130px;
white-space: nowrap;
float: left;
padding: 4px;
}

/* Chapter – Besturingssystemen */
.tablepress-id-1 .row-2 {
font-size: 14px;
background-color: #9FE887;
}

.tablepress-id-1 .row-21 {
font-size: 14px;
background-color: #F7DAD0;
}

/* Row 23 – Specialists */
.tablepress-id-1 .row-23 span {
font-size: 14px;
-webkit-transform: rotate(-90deg);
-moz-transform: rotate(-90deg);
-ms-transform: rotate(-90deg);
-o-transform: rotate(-90deg);
height: 130px;
white-space: nowrap;
float: left;
}

/* Chapter – Programmeertalen */
.tablepress-id-1 .row-24 {
font-size: 14px;
background-color: #9FE887;
}

.tablepress-id-1 .row-45 {
font-size: 14px;
background-color: #F7DAD0;
}

/* Row 47 – Specialists */
.tablepress-id-1 .row-47 span {
font-size: 14px;
-webkit-transform: rotate(-90deg);
-moz-transform: rotate(-90deg);
-ms-transform: rotate(-90deg);
-o-transform: rotate(-90deg);
height: 130px;
white-space: nowrap;
float: left;
}

/* Chapter – Netwerken / Protocollen */
.tablepress-id-1 .row-48 {
font-size: 14px;
background-color: #9FE887;
}

.tablepress-id-1 .row-62 {
font-size: 14px;
background-color: #F7DAD0;
}

/* Row 64 – Specialists */
.tablepress-id-1 .row-64 span {
font-size: 14px;
-webkit-transform: rotate(-90deg);
-moz-transform: rotate(-90deg);
-ms-transform: rotate(-90deg);
-o-transform: rotate(-90deg);
height: 130px;
white-space: nowrap;
float: left;
}

/* Chapter – Databases */
.tablepress-id-1 .row-65 {
font-size: 14px;
background-color: #9FE887;
}

.tablepress-id-1 .row-76 {
font-size: 14px;
background-color: #F7DAD0;
}

/* Row 78 – Specialists */
.tablepress-id-1 .row-78 span {
font-size: 14px;
-webkit-transform: rotate(-90deg);
-moz-transform: rotate(-90deg);
-ms-transform: rotate(-90deg);
-o-transform: rotate(-90deg);
height: 130px;
white-space: nowrap;
float: left;
}

/* Chapter – Applications */
.tablepress-id-1 .row-79 {
font-size: 14px;
background-color: #9FE887;
}

.tablepress-id-1 .row-95 {
font-size: 14px;
background-color: #F7DAD0;
}

/* Row 97 – Specialists */
.tablepress-id-1 .row-97 span {
font-size: 14px;
-webkit-transform: rotate(-90deg);
-moz-transform: rotate(-90deg);
-ms-transform: rotate(-90deg);
-o-transform: rotate(-90deg);
height: 130px;
white-space: nowrap;
float: left;
}

/* Chapter – Hardware */
.tablepress-id-1 .row-98 {
font-size: 14px;
background-color: #9FE887;
}

.tablepress-id-1 .row-114 {
font-size: 14px;
background-color: #F7DAD0;
}

/* Totaal */
.tablepress-id-1 .row-116 {
font-size: 14px;
background-color: #F7A588;
}

At table options i have only selected “row hover highlighting” option, and for database “Use datatables” and “Info”.