| Count | Prefix |
|---|---|
| 106 | spi- |
| 28 | spi. |
| 1 | spi0 |
| 3 | spi1 |
| 3 | spi2 |
| 3 | spi3 |
| 1 | spi5 |
| 1 | spi6 |
| 81 | spia |
| 38 | spib |
| 2,514 | spic |
| 1,841 | spid |
| 1,712 | spie |
| 211 | spif |
| 126 | spig |
| 18 | spih |
| 50 | spii |
| 47 | spij |
| 662 | spik |
| 687 | spil |
| 67 | spim |
| 5,246 | spin |
| 47 | spio |
| 49 | spip |
| 10 | spiq |
| 8,011 | spir |
| 172 | spis |
| 1,096 | spit |
| 9 | spiu |
| 99 | spiv |
| 17 | spiw |
| 32 | spix |
| 4 | spiy |
| 59 | spiz |