| 990 | X | 1 | = | 990 |
| 990 | X | 2 | = | 1980 |
| 990 | X | 3 | = | 2970 |
| 990 | X | 4 | = | 3960 |
| 990 | X | 5 | = | 4950 |
| 990 | X | 6 | = | 5940 |
| 990 | X | 7 | = | 6930 |
| 990 | X | 8 | = | 7920 |
| 990 | X | 9 | = | 8910 |
| 990 | X | 10 | = | 9900 |
| 990 | X | 11 | = | 10890 |
| 990 | X | 12 | = | 11880 |
| 990 | X | 13 | = | 12870 |
| 990 | X | 14 | = | 13860 |
| 990 | X | 15 | = | 14850 |
| 990 | X | 16 | = | 15840 |
| 990 | X | 17 | = | 16830 |
| 990 | X | 18 | = | 17820 |
| 990 | X | 19 | = | 18810 |
| 990 | X | 20 | = | 19800 |