It should be observed in passing that the relative distribution of outgo above mentioned, varies greatly both as between different railroads and, on the same road, as between different years.[33] During lean seasons the imperative need of reducing expenses generally induces the heaviest inroads on expenditure for maintenance of way. Nearly one-third of these expenditures can probably be postponed for short periods without serious detriment to operation; but, of course, there is for each property an irreducible minimum at which economy must halt. On the other hand, the cost of moving each train, that is to say, the outlay for fuel and wages, cannot be greatly cut, although some discontinuance of freight trains may take place. The most readily postponable outlay is therefore found in the department of maintenance of way. Two hundred ties per mile may be annually renewed instead of twice that number for a year or two. Heavy decreases in the wage account for road and track men may be effected, sometimes at the cost of public safety perhaps, but none the less effectively from an immediate fiscal point of view. A series of hard years thus always results in heavy proportional curtailments of maintenance of way expenses. In 1895, for instance, midway between the two worst years of the depression of 1893-1897, only 19.82 per cent. of operating expenses was devoted to maintenance of way, with 15.76 per cent. expended for maintenance of equipment.[34] Six years later, in the full tide of prosperity, the outlay for maintenance of way had risen to 22.27 per cent. With over 350,000 freight cars idle on sidings, as during the spring of 1908, expenditures on repairs of equipment may temporarily be postponed. Depreciation rather than wear takes place. An economy of about five per cent. may temporarily be effected in this wise. It is only with the return of prosperity that the temporary postponement of this expenditure makes itself felt. Economy at the expense of efficiency is poor business policy in the long run. With the revival of activity on the other hand, as in 1898, there may be witnessed a sudden concentration of the postponed expenditures of the preceding years. The Illinois Central was spending $1,400 per mile on maintenance of way in 1905, as against only $1,150 in 1897. A succession of fruitful years may, however, find the property so thoroughly kept up that some measure of relaxation in expenditures may ensue. During these good years with heavy traffic, it is the maintenance of equipment charges which tend to rise. Locomotives and cars are constantly in need of repair owing to hard usage. This was a noticeable feature during the four years after 1900. The Illinois Central, expending only $866 per mile for maintenance of equipment in 1897, laid out $2,200 per mile for the same purpose in 1907.