| Age | No. of nonfault trucks | % of nonfault trucks | Estimated number of trucks | Mechanical failures |
| 0 | 2265 | 11.62 | 17,751,447 | 22 | 1 | 1778 | 9.13 | 13,934,690 | 17 | 2 | 1616 | 8.29 | 12,665,050 | 35 | 3 | 1251 | 6.42 | 9,804,442 | 15 | 4 | 1040 | 5.34 | 8,150,775 | 25 | 5 | 798 | 4.10 | 6,254,152 | 26 | 6 | 751 | 3.85 | 5,885,800 | 15 | 7 | 847 | 4.35 | 6,638,179 | 37 | 8 | 922 | 4.73 | 7,225,975 | 32 | 9 | 977 | 5.01 | 7,657,026 | 31 | 10 | 957 | 4.91 | 7,500,280 | 40 | 11 | 923 | 4.74 | 7,233,813 | 37 | 12 | 699 | 3.59 | 5,478,261 | 28 | 13 | 566 | 2.90 | 4,435,902 | 21 | 14 | 550 | 2.82 | 4,310,506 | 30 | 15 | 583 | 2.99 | 4,569,136 | 28 | 16 | 514 | 2.64 | 4,028,364 | 28 | 17 | 483 | 2.48 | 3,785,408 | 32 | 18 | 421 | 2.16 | 3,299,496 | 30 | 19 | 312 | 1.60 | 2,445,232 | 24 | 20 | 248 | 1.27 | 1,943,646 | 26 | 21 | 202 | 1.04 | 1,583,131 | 13 | 22 | 148 | 0.76 | 1,159,918 | 6 | 23 | 124 | 0.64 | 971,823 | 10 | 24 | 93 | 0.48 | 728,867 | 7 | 25 | 73 | 0.37 | 572,122 | 10 | 26 | 56 | 0.29 | 438,888 | 9 | 27 | 63 | 0.32 | 493,749 | 8 | 28 | 43 | 0.22 | 337,003 | 6 | 29 | 49 | 0.25 | 384,027 | 9 | 30 | 24 | 0.12 | 188,095 | 4 | 31 | 28 | 0.14 | 219,444 | 2 | 32 | 8 | 0.04 | 62,698 | 0 | 33 | 12 | 0.06 | 94,047 | 2 | 34 | 7 | 0.04 | 54,861 | 3 | 35 | 9 | 0.05 | 70,536 | 0 | 36 | 8 | 0.04 | 62,698 | 2 | 37 | 9 | 0.05 | 70,536 | 3 | 38 | 13 | 0.07 | 101,885 | 3 | 39 | 5 | 0.03 | 39,186 | 1 | 40 | 9 | 0.05 | 70,536 | 1 | Sum | 19,484 | 100.0 | 152,701,631 | 678 |
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